So the upgrade installed Firefox 3, which is a beta. While Firefox runs well, version 3 doesn't support several of the plugins/extensions I was using. In particular, I spent a couple of hours figuring out how to get Firebug to run in 3. Then I realized that Selenium doesn't work either. Then I realized that the version of Firebug for Firefox 3 doesn't work. I tried to downgrade to Firefox 2, but wasn't successful. I'll need to spend more time at that, since I do need to downgrade. I do need to run those plugins. I tried the naive approach of removing Firefox 3 with Synaptic, and then installing Firefox 2. All that did was wipe out all my cookies and didn't actually change the version of Firefox. I didn't have time to spend on figuring it out, but the bottom line is that I was surprised that Ubuntu forced an upgrade to a beta version of an app and lost existing functionality without asking.
While Firefox 3 seems to work well (the plugin/extension issue aside), it's butt-ugly. The components don't (can't?) follow the look and feel of the rest of my apps.