The post I just wrote was sucked into the ether and required me to login again. It's at least the tenth time I've logged in today to this site or the blog site. Clearly they're having cookie issues in the upgrade.
You'd think, "Duh, AJAX Extensions aren't installed." That would be plausible, but the ScriptManager control is on the pages, so if it weren't installed, then the page would fail outright. Instead, it's executing, but missing important pieces. web.configs are the same other than the database connection strings.
We opened a ticket with Microsoft, and the first guy couldn't help. They transferred us to an IIS person, which I didn't understand at all. Now it sits with someone in the AJAX group.
The overwhelming theme with the AJAX framework, for me, has been that it just doesn't do the "xcopy" deployment thing very well. It's very frustrating. I hope in the next version of the framework, when it's no longer an "extension," so you don't need several dozen lines in web.config.