Nick Goracke said:
Is the 2 player mode simply having one person use the remote while the other uses the nunchuk?
(That wouldn't be possible, because then Mario couldn't jump, but I digress.)
It's better than that:
1p controls the game as normal, while 2p uses a
second remote that can do everything 1p's remote can PLUS if 2p holds down the A button you can (to a limited extent) manipulate certain objects (e.g. Hit those rubbery bushes)
It's a little disorienting at first to have a second, similar cursor on the screen, but after you get used to it 2p can really help you out by collecting things/stunning enemies while 1p focuses on getting through the level. I played 2-player mode with my girlfriend for about an hour last night and it was a blast, on both ends. It's nice that 2p can jump in and out whenever.
...
And as for jumping, it's not like it's GONE. In fact, sometimes it's the better option, since you get a coin (which can heal you, of course) instead of the star bits.