This just seems kind of wrong. I’ve never been a big fan of rag doll type physics, it makes the characters look just like the name implies, stuffed dolls. Now while the game is definitely listed on Havok’s site, I can’t help but notice that Guitar Hero III is also listed. So take a medium sized grain of salt with this “news”. Smash Bros. Brawl will probably be using one of the other products that Havok offers. In fact, take a look at the statement right above the list of games:
The following game titles on current and next-generation Wii, Xbox 360 and Playstation®3 platforms will be released utilizing Havok products.

