No, not Mario games plus Sonic games, but rather Mario & Sonic at the Olympic Games has sold over 5 million copies to date. Between the DS and Wii versions, this game is blowing up in every territory, and that’s before the expected sales bump that the game will receive once the Beijing Olympic games roll around. By most accounts the game was merely average (I never tried it), but this is definitely a sign that Mario and Sonic still have some serious draw.
So does this mean that we’ll be seeing more Mario and Sonic crossover titles? Maybe. Sonic is already in Super Smash Bros. Brawl, and I don’t think it’s too far-fetched to see Nintendo and Sega getting the characters together again in some sort of racer or other type of party game. With the sales that this game has received, you can count on seeing Mario & Sonic at the Winter Olympic Games two years from now.