Here is a quick review of MarioKart DS. I only bought it today so these are only my initial impressions.
Firstly MarioKart DS is much the same as any other version of Mario Kart - why mess with something that works so well - but only better. Better because this game is so suited for the Nintendo DS - it just feels right.
There are heaps of new levels as well as levels from the SNES, N64 and GameCube versions, and a good variety of game types; Grand Prix, Time Trials, VS, Battle and Missions, as well as multiplayer, to keep you engaged for a long time.
The graphics are great, with no slow down in framerate
The games controls are excellent - the lack of analog controls is not an issue. The touch screen really only needs to be used for the menus. This is a game that anyone can pick up and play and have heaps of fun.
I haven't had a chance to try out multiplayer so I can't comment on it.
Over all MarioKart is a whole lot of fun and I can highly recommend it.