For those interested, Darrin sent me his catalog which I was able to upgrade successfully on my system in 22 minutes. I instructed Darrin to try again and he let it run much longer and eventually it finished.
Most of the work done in upgrading a catalog happens inside the database engine and there isn't much that can be reported in the UI.
Just give it some time for larger catalogs (Darrin's had over 1.5 million images in it.)
-Kirk