Um, this is a feature not a bug. If you're syncing with an iOS device in Finder, well cancel that first . Lots of applications can prevent rebooting to avoid data loss. Again, this is a GOOD thing. Sheesh.
He said he couldn't cancel. The article is not that long, it's not hard to find.
I'd still rather my OS refuse to shut down because it thinks a process could lose data.
Because at the end of the day I can always just hold down the power button to turn it off, you know?