Yeah, I agree on the "not many extra characters" thing. I mean, there is such a thing as just too freaking many.
One of the charms of the old games was that you could find a character you really loved playing with, and you weren't overwhelmed with so many choices. Anyone else thing it's getting a little insane with certain fighting games? I mean, I can see, in a few years, Capcom releasing a new Street Fighter/SNK/Marvel/DC fighting game or something and "OVER 176 CHARACTERS!!!!" typed flashily on the cover. You can't even learn all the moves much less get Ryu/Ken comfortable with any of them...haha. You know?
So, hopefully, a few more characters will be added (which even that isn't necessary, I would say), but it will still be a very tight set of core characters with even more nuance, perhaps, in their control.
Another thing is that though I LOVED N64's Mario Kart, I still prefer the SNES version ever so slightly. To me, and this is probably going to be met with great argument, the old one was a bit more about RACING instead of what I consider to be an over-reliance on the item boxes and their so-called randomizing. I'm sorry, but when it becomes a good strategy to stay in 5th or 6th place until the final lap when you can get all the good items and overtake everyone at the last second, well, thrilling though it is, it gets old. I think.
I think it would insanely cool if the game became even a bit more like the ultimate Mario Kart rip-off, Crash Team Racing, which I thought was incredibly fun as a racer, although I never played it much multiplayer-wise. It had some great additions that really shot adrenaline through the stale genre. Of course, I won't be so naive as to think I could give Nintendo advice (much less Miyamoto) on this...haha. I'm sure it'll be everything we want and more, although I'm guessing there's no guarantee for the online thing, so if that's a deal-breaker, I feel sorry for you...haha.