No problem -- the expansions and the base game are intended to have the same version numbers in general, but... well, it's a long story. At any rate, I don't see a reason to make non-expansion customers download 100 MB of content that they won't actually use; as we do more expansions, that number will only grow. This way people download what they want, and it's very easy in general.
The expansion and the base game always share the same numbering system, so there will always only be one "current" official version and one "current" beta version at most, regardless of how many expansions there someday are. But, in the case of the internal content for the expansion, sometimes that might have a different internal version number (if we update an image, or text, or what have you).
Blah, it sounds more confusing than it really is, mainly because I messed up one thing with the expansion updater, and that's causing me to have to go through some extra gyrations at the moment. But it's all good, I've got it worked out and there will be expansion availability shortly.
Thanks for your support, all! And I'm glad you're looking forward to the music.