Personally I'm much more excited about this than I was with the Wii. HD graphics (equivalent to PC directx9 technology while 360/PS3 are still in the dx7-8 days), a more traditional controller (I wasn't a fan of the Wii mote), and they've announced that there will be a new Super Smash Bros. and "realistic" Zelda game for the console. Of course, I'm sure there will be some fun Mario games and a badass photorealistic Metroid game. :3
Nintendo's plan with this console is to hang onto casuals they won over with the Wii, but also to win back their older hardcore gamers.