For those who love source code…
There is now a new git repository with the full context source code at http://dl.contextgarden.net/distribution/git/. There are two branches one with the stable release of context (aka current) and one with the beta release. Just do this:
git clone http://dl.contextgarden.net/distribution/git/
Now you have all stable releases since 10/1997 and all beta releases since 5/2009. The stable branch is the default branch, to switch to the beta branch you can do something like
git checkout -b beta origin/beta
update 2009-07-17: The repository is synchronized every day shortly after midnight. So todays stable will be there tomorrow morning.