We missed this one, but it's worth users checking out if they haven't already. If you own GarageBand for iPad and have a Mac with GarageBand installed, you may want to run that update. A while back Apple added support for opening GarageBand files created in iPad within the desktop application.
Other than that, Apple mentions the typical "This update improves overall stability and addresses a number of minor issues, including the following."
As a side note, this kind of makes us wish we hadn't deleted the software off our Mac. It just never interested us, but it's been fun to play with on the iPad. Maybe we will just reinstall. We'll get around to that, eventually.
We also have a review of the iPad version, which we ran a few weeks back. We had a good time, and think it's definitely worth checking out. As we said before, we were never huge fans of the desktop version. This one changed our thoughts on the software, but we're not serious musicians, we just thought it was fun to play around with sounds.
See our review here.
You can download the update and check out additional, more detailed information at Apple's website.