Played both versions at school and so far:
HOLY S***! New moves for the regular characters and new slick and badass characters from Bob to Zafina... crazy and stunning stages (and yes you can hit the animals!!

Sound: while most characters have recycled voices, some like Law have new ones (however... when talking... I heard new voices... for Paul and Julia); soundtrack is very impressive. My favorites are the Jungle and the Casino themes.
However... PS3 version has better control response. 360 version (which I'm gonna be stuck with in the end) does not, in terms of directional buttons.
So my score is:
Xbox 360: 8/10; PS3: 10/10 (reason for the 2 lower points for 360 than PS3 is because of the controls).