Pallete Swapping - Something relatively small but I would love to see multicolored Yoshis in Mario Kart 3DS's multiplayer or Online mode.  Also, instead of having 3 Mario's in one race, why not have a Fire Mario, regular Mario and Cloud Mario in one race.  Maybe Pallete swapping for karts too.

Removal of Snaking - Yes; not everyone snakes, but it punishes those who choose not to do it and gives those who do choose to snake, an unfair advantage in time trials and multiplayer races.

Return of Mission Mode - Quite possibly the best new feature in Mario Kart DS, I'd love a reappearance in its successor.

A new Wi-Fi ranking system - The Wii format doesn't work well for those are just plain unlucky.  I know from experience that it sucks to lose 400 VP from one race because you didn't have red shell fodder or you're hit by a Spiny Shell in the last lap and the finish line is right in front of you.  Especially when you're only getting 15-20 VP from getting first in races with less experienced players.  Also the DS format doesn't work because it encourages disconnecting/ragequitting and it doesn't make immediate success worth while because you have to win 1st in an entire GP or get a lose/disconnect.

Rebalancing of Drifting - In Mario Kart Wii, inward drifting is incredibly broken.  I really don't know how they could rebalance it but maybe buff the mini-boosts for outward drifting vechiles and nerf the mini-boost of inward drifting vehicles.

Bikes and Karts - pretty self explanatory.

Miis Playable - once again self explanatory.

Optional Team based Battle Mode - Yet again fairly self explanatory.

Meh, If none of these appear in Mario Kart 3DS I'm sure I'm still going lose hundreds of hours playing it.

- How about GETTING RID of the friend codes?

- i'm hoping the 3DS has a proper friend system where you see what your friends are playing, all games not just MK, also you should be able to chat with them. In-game or not.

- NO bikes! It's Mario KART 3DS, not Mario BIKE 3DS. IMO if it has bikes as well it should be Mario Racing 3DS.

- FFA battle mode

I agree 100% on the palette options and the return of the Missions.

Great ideas and I agree with you completely. The inclusion of Mii's in Kart Wii was a great idea, and a feature me and my friends loved, either because of a race featuring Gandalf, Jesus and Hitler or a gigantic Stalin face appearing above a tunnel.

Snaking was already nerfed in MKWii.  I wouldn't want powersliding removed entirely, it wouldn't be Mario Kart anymore.

I agree with the rest though.  The only other thing I can think of is taking a hard look at battle mode and really improving it.  I miss the MK64 glory days (Block Fort 4-eva!).

I want to drive bob-bombs again!

I said some of these things in the vein of this game being more like Mario Kart Wii and less like the DS game.  Just in case you didn't know.

I like snaking, but I do agree with most of your suggestions.

Also get of of friends codes (though that doesnt apply to just mk3ds of course, but all nintendo games)

My friend treats snaking like a religion, proclaiming its goodness and importance to winning and becoming a competitor. 

Then I hit him with a red shell and he slips of a banana into a pit of lava and he remembers the type of game we're playing.

Ahh, snaking. Definitely a game breaker for me, as i hate being told how i *should* play (within certain parameters anyway), and Snaking was definitely one of those things, especially because it left you the alternative of "snake or lose."

I think some of the items, like bullet bill and blue shell, are annoying. I'd love to see a smash bros type item system in which you can turn off certain items.  Perhaps you could even do a voting system for online play.

More importantly fix battle! MKW battle was awful!