That update arrived Thursday in the form of , which promises support for opening projects imported from .
The 47MB update is available from as well as via Software Update. Note that after installing the update, if you try to open a project exported from the iPad version of the app, GarageBand will prompt you to download a second patch for compatibility. After everything's installed, GarageBand '11 will support opening any project you've exported from GarageBand for iPad, allowing you to expand upon your seven-track-maximum masterpiece.
In addition to support for iPad files, the 6.0.2 update claims to improve overall stability while tackling a number of other minor bugs.
You'll need to be running Mac OS X 10.6.3 or later to install the GarageBand update.