It would *seem* possible, but, I don't know of a way.

What a pity.

Wait for the next firmware update.  Apparently even XViD (or however that's capitalized) support is included.

According to Google search results, this is all rumor, but it would be really rad if it were true.

http://www.google.com/search?num=100&hl … +07+update

So hold off for a few months before you get all hacky hacky and void your warranty doing whatever.

Tversity will transcode your video files to a format the Xbox can play. It takes a beefy computer but it does work.

http://tversity.com