I, as a developer, am excited about the possibilities of the Wii console/controller combination, and about the upcoming influx of new target audiences for games (instead of just 18-25 males).
Hopefully, that means that games that would have been impossible to make, play, or get publishing deals for, will now be developed - and I might be one of the ones who gets to develop them. Wii development is significantly cheaper than PS3 (I do not know numbers for 360 dev) and as such, publishers may take more innovitive risks with games instead of endlessly demanding GAMEX++ or GAMEYWITHACOLOURCHANGE.
As a player, I hope that the controller will make games new again for me - I'll be able to play games with 'non-gamers' and I'll have a whole new way to enjoy my hobby. I'll have games that wouldn't be possible on other machines, and as I don't actually care much about graphics, the one 'down side' to the Wii I can safely ignore. I look forward to playing Tennis with my bf's mum and granny at Christmas, to teaching my mum how to play Wii Bowling at New Year, and maybe even beating seven shades of purple out of my brother's Mii in Boxing while I'm at it.
People are worried that existing game genres might not transfer well on to the Wii - I'm looking forward to the new game genres that it may spawn!