Typical Mario Sonic game nothing new here. Only Mario & Sonic fans will get something from this. Very predictable.
Now for the Cons firstly i thought there would be an improvement with the main aspect of the game which surely is breaking records and storing them but this can only be done depending on who logs in. If you break a record while playing against someone else and logged in to their profile then they claim the record under the character you picked, which goes against the whole aspect of the game. Also this game has been targeted towards all the dream events which lets be honest has nothing at all to do with the Olympics. Perhaps Sega could have made a separate gamed called Dream Events. The other real downside is how can they pack 3 times more Olympic events into the small DS version than the Wii?!
If you are a big fan of Mario sonic games i am sure you will add this to your collection but if you already have the 2008 Olympics then don't waste your money on this one.