In reply to Alec.

Hi Jason,

I promised you a plugin which would automatically update your WordPress.org plugins from GitHub repositories. When updating is a single big red button, it's a lot easier to keep WordPress SVN release versions up to date. Here it is: GitHub2SVN. We'd be delighted to see some development forks and will process pull requests very quickly.

Addressing your issue of updating plugins which are on GitHub directly, there are two options: the rather elaborate GitHub Updater (322kb/1658 commits) or the very simple External Update API (17kb/94 commits). External Update API comes set up for GitHub by default. My preference would be for the latter as it's flexible and lightweight. The more sites and projects we build and maintain over many years, the more attractive simple and lightweight code becomes.