Actually, he does use Capoeira at one point at the end of the 15-minute trailer(I'm just saying he uses it -- I'm not saying it's his style). It's not too obvious, he doesn't ginga(the moving stance) or au(cartwheel and the variants) or whatever, but he does an esquiva (where he sweeps his leg to the side so he can get up) and a one handed macaco(one handed backhand spring).
** I just watched it, he also does a flic-flac, an aerial and a b kick. Those aren't only capoeira moves(they also use them in other martial arts) but that macaco alone is enough to say that it's what he's using.
...Then you have that spinning kick move. I never knew the name.**
Here, I'll post a link.
http://youtube.com/watch?v=sklto4QOukQ&search=Metal%20Gear%20Solid%204%20RaidenIt starts at [1:17]