Something makes me doubt that this will be better than Mario Kart DS, the best game in the series IMHO. The fact that they changed the powerslide boost by removing the flicking of the joystick (or the D-Pad in the DS version) back and forth in order to build the boost kind of just annoys me. Now it just builds the boost automatically the longer you slide, and that looks as if it will be annoying and harder to accomplish than how it was even done in the N64 version.
I know that they removed it because of the snaking in the DS version, but at least in the N64 version it was essentially impossible to do such a thing. They could have made it like that version I think. Also, from all that I have been reading on IGN the past couple of days, they said that it hardly gives you a boost and by the time that you notice you are going any faster, the boost is done with. In the DS version it was definitely a noticeable boost, almost as much as a mushroom would give you.
I'm expecting this game to get around a 7.0 out of 10 rating. Just the fact that they haven't been hyping this game up or even as much as give it half the attention that games like Metroid Prime 3, Super Mario Galaxy and Paper Mario got before they were released just makes me skeptical. The game comes out in just over a month, and that is not a good sign.
I do however think that the 12 person WiFi races will be some sort of a saving grace though. Hopefully they won't follow the same suit as they did with SSBB and allow for things like Leaderboards, customizable races including the ability to turn certain items on / off, and let people see other players names! Even Geometry Wars: Galaxies for the DS lets you see a Leaderboard with player's names.
Only time will tell though, and unfortunately that is only several weeks away. I'd actually like to see them delay this game so they could put more time into it. It seems as if it has been quite rushed, only being announced at E3 last year. I could be completely wrong about this game, and I hope that I am because I really would like a new Mario Kart that didn't suck like Double Dash did.