Nothing new.

User Rating: 6.5 | Mario & Sonic at the London 2012 Olympic Games WII
his 'new' mario and sonic game is, uh, not that new at all. Most of the sports are from the original mario and sonic at the olympic games, but with little tweaks. Some of them, I have to admit, put the wii's motion-sensing to good use, but those are rare. The thing is, we've had two mario and sonic olympic crossovers now, one winter, one normal. So this one's simply taking concepts from the original and simply improving them. There's lots of fun to be had here, but the same could be had in the original.
Minigames are generally designed well and are great in multiplayer.
As well as the main events, there are so-called 'dream events', which are different takes on a particular sport, but done in a way that wouldn't be possible in real life. It's a good idea, but for a lot of the minigames, you can't even tell which sport they're meant to be like, making them feel like mario party minigames or something. Regardless of that, they are a lot of fun, despite being a little too cluttered.
There's also a multiplayer mode that takes place in London, which has you run around in a miniature model of the city. Every so often you play minigames, but a lot of it involves playing in London. You need to do your best there to shift the tide over to you. But this mode is simply lacking in ideas and is tedious to play.
Mario and Sonic at the London 2012 Olympic Games isn't a bad game, but it doesn't do much to distinguish itself from the original.