drunkencoders.com announced their 5th Annual Wintery Game Coding Competition a while ago. Entries can be submitted till March 19, 2010.

Goal:

Create a Nintendo DS or GBA game with a winter or holiday theme. Be it Wack-a-Santa or nuclear snowball fights with diminutive elves we want to see your wintery creations. Now accepting Wii and Gamecube entries (judged by the same criteria but awarded prizes from a seperate prize pool).

http://drunkencoders.com/2009-winter-game-programming-competition/