The Husks from Mass Effect are some scary dudes.
Trishka was pretty annoying in Bulletstorm and since it's being made by the same developers I hope they tone down the 'badass chick' attitude on the female characters in GoW3.
Also, Beast Mode sounds promising.
I have both a PS3 and a 360, but as of late my 360 has decided to overheat after 10 minutes of playing any game. My PS3 has never been happier.
The beta alone could be GOTY.