Livestreaming would broadcast it live to sites like Ustream.com or Justin.tv
Pro: Instantly there, live, audience interaction
Recorded gives you the ability to upload to different places like Vimeo or YouTube
Pro: Gives you time to edit it, take out things, add effects, titles whatever
Most of the Livestream sites archive the footage as well, so even if you stream it to Justin.tv, it'll still be there afterwards so people can watch it at their leisure.
If you're not planning on doing any post-processing, or putting it somewhere that it can be monetized (like YouTube) I'd probably recommend going with one of the live sites.
However, if you happen to be bandwidth challenged, remember that simultaneously uploading all that video WHILE you're running your game, and your voice/video chat all at the same time might strain your connection. Might want to do a short pre-test first to make sure that your connection can handle it.
