I'd like to see Santa Monica do Heavenly Sword 2 actually. Bring back Andy Serkis and all actors that would still have characters in the game, possibly someone who worked on the original story. I would love to see what Santa Monica could do with the Heavenly Sword framework of lots of enemies on screen and the hack'n'slash.
I never felt the hack'n'slash in Heavenly Sword was really up to par, so Santa Monica could make it good (just not a GoW clone hopefully), and my only real worry would be that they decide to go the God of War route and turn it into... well... a bloody mess (by which I mean lots of gore ). That wouldn't be cool.
I would love to see the Sixaxis use from the first game return, because those were definitely some of the highlights for me.