Yesterday I migrated the image Gallery from Gallery v1 to Version 2.2. The process was quite painless, thanks to the excellent documentation. Just one caveat: in version 2.2, the Gallery v1 migration plugin has to be downloaded and installed first, it did not ship with the "Typical" installation package. Oh, and make sure you have configured PHP to be able to use lots of memory, too! I had to change the settings so it was able to allocate around 42 MB for importing my 3600 images from the previous version...
I hope the migration was successful, please let me know if you notice anything weird! One thing I really like about the new version is the WebDAV support - now I can simply copy new pictures from Konqeror or any other KDE application into the Gallery.