The Winter Fun Pack 2004 is now available to download.
There's a bunch of things included for Windows Media Player 10 such as skins and new power toys. There's a cool looking addin to add your currently playing music to your email signature when you send email which I'm going to have to play with.
There's some fun stuff if you're into digital photography like a wallpaper changer and Photostory 3.
Most exciting though is the inclusion of TweakMCE for Media Center 2005 users. You can use TweakMCE to tweak some Media Center settings that aren't normally exposed such as skip and replay times and some remote control settings so you set your media center to only respond to a certain remote control. This is great if you have an Extender near your PC as they both use the same remote control.