Solution: ConfigMgr2007 SP2 Setup stuck in Upgrade status
I recently ran into this issue a couple days ago and didn't see a whole lot documented on it so I thought I would do a quick write up here. If you're trying to upgrade some of your site servers to SP2 and run into an issue, this should get you going again pretty easily.
The Configuration Manager Support Team Blog : Solution: ConfigMgr2007 SP2 Setup stuck in Upgrade status