Picked this up yesterday. My store is slow. Immediately, I love the cosmetic improvements they made to the game. Now it's in 480p and 16:9 widescreen, and there's a *lot* more Voice Acting. I haven't gotten far enough to see any new tools, but i'm looking forward to that.
The addition of Online Leaderboards is novel, and something that would keep score junkies coming back to it.

I'm really interested to try some of the co-op mode (though it's not online). In the previous Wii game, you could sort of do Co-op with one person on the nunchuk while the other was on the remote, kind of like a 'nurse, hand me this tool' kind of thing, but this game is 2 doctors operating simultaneously. I can imagine some of the harder stuff from the last game going much smoother with an extra hand, so that really has me interested in trying it. If only I had someone to play with... the only other person I know who would buy this game is going back to Canada tomorrow for school.

But yeah, fan of the games. This series is one of the best 3rd party franchises on the Wii.