Since we have quite a wealth of plugins on GoogleCode, BitBucket and some on GitHub, I have added support to the community package wiki for links to non-GoogleCode packages as well.
I did an quick scan through the Plugin Announcements forum to get an initial listing. If you have commit rights to the GoggleCode repo, you can simply add an entry to the /cgi/externalPackages.py listing, and index page will be regenerated accordingly. Otherwise, you can email me (barney_dot_williams_at_gmail_dot_com) to request an addition. I have not added support for stuffing the external packages into <plugin>.sublime-package files, and not sure if it is worth the effort. This prevents them from being available via the PackageDownloader, but not sure how many users utilize the downloader.
At any rate, this gives us a central place to list ALL plugins publicly available, which is a good thing.
Go to http://sublimetextwiki.com to take a peek.