It all depends upon who you ask. Technically, and from a literal standpoint, wu shu is made up of two words, "wu", meaning "martial, relating to the military", and "shi", meaning, "arts, a tradition, a study". So, wu shu means, in the literal sense, martial arts. Gong fu (kung fu) technically doesn't mean karate, or martial arts, or the like. It refers more to "training, process of training". So, wu shu and gong fu don't technically mean what we think they mean.
According to Shi Xing Xi, wu shu and gong fu are the same. Or, almost. According to other monks, gong fu refers to the process, or act, of training or studying the Shaolin martial arts, and it has been simplified to just mean the martial art itself. So, if one is learning Shaolin gong fu, one is learning the Shaolin martial arts. With the ever changing climate in China, and the emergence of the Shaolin martial arts now more as a competitive style and exhibition style (as opposed to the traditional fighting skills passed down by the Shaolin Temple monks), the term "wu shu" is sometimes thought of as referring to the competitive and exhibition style aspect of the martial arts, and gong fu, is more likely to be understood as the tradition, the training, and the study of traditional (noncompetitive style) Shaolin martial arts.
This whole concept has led to a lot of confusion, in that, many foreigners go to the Temple to train, and leave disappointed, thinking that what they've seen is just to "flowery", or "ballet like", or, exhibition dance like. There are a few ways to look at this. First, the martial arts typically don't show the fighting aspects to the uninitiated or untrained. Hidden inside these elaborate dance like moves are real (and effective) fighting skills. With the advent of more competition, and the increase in the training of martial arts in China, the traditional gong fu is altered, and in some cases, exaggerated, in an effort to make it appear "more beautiful", or, more embellished, all in the effort of showing expertise and precision in light of the competitive atmosphere. There are still fighting techniques hidden inside these moves, but kicking higher and higher, and squatting lower and lower, though essentially derived from effective fighting techniques, is more conducive towards competition than fighting. If one watches some of the older monks perform some form, one would notice that the older monks do their forms in a more upright position, as opposed to the lower stances used by the younger students. No doubt physiological changes with aging make the lower stances more difficult, but, one must also appreciate the fact that the older monks, trained many years before the advent of all of this national competition, are performing the forms as they learned it. True, at their age, it might be more difficult to do the lower stances, but, rest assured, some of these guys are pretty damn flexible. Fighting in a lower stance might be more conducive to praying mantis style, but in some other forms, a higher stance would be more desirable. There does appear to be a difference in form presentation between the generation groups, and as I've been told, when the students train for competition, the lower the stance the better, the higher the kick, the more impressive. Stances have definitely changed with the changes in the "uses" of the martial arts. Now, wu shu seems to be more associated with competition styles, gong fu more associated with the traditional forms and uses of the art.
A fellow Shaolin aficionado, student of Shi Xing Xue, from a Shaolin gong fu school in Scandinavia, quotes gong fu with a deep insight as being the following: "I feel Shaolin Gong Fu works in harmony between body and mind in a way that I haven't seen in any other martial art. Focus, momentum, explosiveness, relaxation, tuning of the body, and the overcoming of fear. It's not only about not fighting people, but about not fighting yourself either - hence 'Gong Fu'" (Björn Javefors, www.shaolin.nu).
So, what really is taught now at Shaolin? Well, a combination of both, actually. The older monks still teach traditional forms to their students, but, because of the national movement towards encouraging competition, competitive wu shu has got to be taught. If a school doesn't win competitions and get trophies, it doesn't get fame, and if it doesn't get fame, then it doesn't get more students. Kind of a self feeding vicious cycle. But, traditional forms are still taught to some degree, and, interestingly enough, we're seeing a resurgence in traditional gong fu now in Chinese competitions. Now, there is a category called "Traditional Shaolin competition", whereby students compete in tournaments in traditional gong fu demonstrations. But, some of these traditional gong fu competitions don't highlight the traditional forms as they have been taught over the ages; these traditional competition forms are melanges of bits and pieces of traditional gong fu. Confused? Well, a lot of people are. Let's organize this train of thought a little.
* Competitive Wu Shu: Remember one thing, when talking about how Shaolin doesn't teach real gong fu anymore, that is, these comments of "It's all just wu shu". Just remember, that wu shu originates from traditional gong fu. But, it's been changed, in a few ways, to make it more "competition" capable. A wu shu form does not generally remain restricted to a line, as most traditional forms do; competitive wu shu forms will find the practitioner moving in all sorts of directions. The kicks are higher, the stances are lower, the punches have straightened arms, the moves are more "dance like" and "flowery". It is quite pretty to watch, and it does take some skill, as it does have acrobatic components. But, always remember, it derives from traditional gong fu, and as such, does have fighting applications buried within the movements.
* Competitive Traditional Shaolin Gong Fu: There are now competitive categories in Chinese tournaments which allow students to compete with others via demonstrations of traditional gong fu. But, generally, the competitions do not use the traditional forms as they have been taught over the centuries. The competitive agencies get together, and "create" new forms, used specifically for competition, the components of which are taken from sections of real traditional forms. In Dengfeng, there are some old masters who get together with some of the young masters (my master, Shi De Cheng being one of them), to create and derive these traditional competition forms. Basically, they take bits and pieces of true traditional forms, and piece them together, to make interesting competition forms. These forms are not considered to be "wu shu", in fact, the are called traditional competitive forms. The actions and movements performed within them are the same as those seen in true traditional Shaolin forms.
* Traditional Shaolin Gong Fu: These are the forms that have been taught, essentially unchanged, over the centuries. These forms are still taught by some of the older masters, but, unfortunately, many of the current students in China's Wu Shu schools, do not learn all of them. An example of this, would be my master, Shi De Cheng. In his school, he does not teach the students some traditional forms, such as Da Lohan, or, Chi Xing Tong Long Chuan, because, well, for future competitions, there is no reason to. (In fact, he hasn't taught those forms to his Shaolin monk disciples, who teach at his school. And some of these traditional forms are not being taught to the current up and coming Shaolin monk generation at the Shaolin temple wushu guan). Over the years, he has taught them to me. My interests lie primarily in traditional gong fu, and not, with competitive wu shu. Which, raises an interesting question, and that is, what will become of the real, traditional Shaolin gong fu in the future?
As for gong fu versus kung fu, it's all a matter of semantics, but, at least, they're interesting ones. Sources of mine explain that in mainland China, the Mandarin for "gong fu" is, well, "gong fu", pronounced with a "g" sound (almost like "gung"). In Hong Kong, where Cantonese is prevalent, the pronunciation of the same word sounds more like "kung" with a "k" sound (as in "kung"). Since the majority of the martial arts that we have seen here in the US from many years back originate from Hong Kong émigrés, (and since most of the movie pictures came from there), we in America refer to mainland China's "gong fu" as "kung fu". (Same goes for our Chinese food, though, in some major cities, we're starting to see cooks from mainland China here). Interestingly enough, our usage of the term "kung fu" is now working its way back to mainland China, where you see some mainland Chinese referring to their "gong fu" as "kung fu" or even "kong fu". Confused? So is everybody else. Leave it to us Americans to screw a good thing up.
To put all of this into some sort of relevance, I look at it all in a more simplistic manner. If you happen to have the opportunity to live in Shaolin village, train endlessly with the monks, eat in the "restaurants", use the "facilities", tolerate the "way of life", survive the lack of "creature comforts" (heat, hot water, and, well, water...), deal with the "environment" (bugs, humidity, heat, cold, rain, snow, etc), you'll eventually understand what I mean when I say, "It's all gong fu".
But, it all depends upon who you talk to.