The concept of streaming such a thing is great. Except that twitch.tv seems to be for gamers and windows only. And I can't find any description on their website of how to download and run even the Windows software that would stream the video.
If you're interested in streaming more general programming, check out twitch's sister site, justin.tv - more specifically the new Creativity category (http://www.justin.tv/directory/creativity). We have a bunch of awesome people doing live coding already, and we're very interested in helping more people get started. Feel free to email me - bill@justin.tv - if you need any help.
You can use Flash or Livestreamer on Linux and presumably OSX. There are also apps for Android.
Crap, so if I wanted to do the ludum dare I'd have to use windows? :/
George Broussard (linked above) is streaming from OS X.