I'll be merging as soon as I release beta and again after final.
The problem with changing the nightly tarballs to the tagged branch is we'd have to switch back after the final release and that's just a little more sysadmin overhead than I have time to deal with, or anyone else at the moment really.
I don't expect it to be a big deal to see these out of synch for a few days, in practice.
The real answer is to make our software bug free so alpha == beta == release! :)
