Super Mario Galaxy 2 details

– Yoshi can eat enemies, flutterjump, eat blimp berries to inflate/float (hold A button), Dash Peppers make him go faster
– Side-challenges for more stars
– Game has some throwback music from games like Super Mario World
– Again, game will have orchestrated music
– Sky Station Galaxy, Spin-Dig Galaxy, Hightail Falls Galaxy, Tall Trunk Galaxy, Upside Dizzy Galaxy, Bowser Jr’s Fiery Flotilla, Supermassive Galaxy, Bowser Jr.’s Fearsome Fleet, and Flip-Swap Galaxy confirmed
– A lot of earthy backdrops
– Huge enemies in Supermassive Galaxy
– Flip-Swap Galaxy has a timed purple-coined challenge
– 60 FPS

Source, a few more details here