Well, as a one-stop shopping sort of thing for all things Starcraft2, any of these may be a good place to keep an eye on:
http://starcraft2.filefront.com/http://www.moddb.com/games/starcraft-iihttp://www.strategyinformer.com/pc/starcraft2/Personally, I bookmarked all 3, since even though there will be some overlap, each will still contain files not found in the others.
Moddb is my favorite because mod makers will keep regularly updated progress reports on their mods in development, and you can track your favorites and receive notifications of updates.
“The greatness of a nation and its moral progress can be judged by the way its animals are treated.”
- Mahatma Gandhi