Yeah, we had that too!
Add/Remove programs didn't work, and not even the Swiss Army Knife that is CCleaner! Windows 8 Upgrade just couldn't get past uninstalling the Intel PRO/Set Bluetooth adapter.
Thanks to this post on the Intel forums by AtlanticBirD, the solution turned out to be quite painless.
Presumably you'll have selected the option to keep all your apps, documents and settings in place for the upgrade.
If you're stuck on the screen asking you to uninstall the Intel PRO/Set Wireless Bluetooth adapter (for the umpteenth time), click "Back", and select the option to only keep your personal files.
Click next once.
Before you go ahead and upgrade on the next screen, click "Back" again, and choose to keep your apps and settings this time.
Cross your fingers, hold your breath, and click Next...
Low and behold, you're good to go!
Hats off to you, AtlanticBirD, you've saved the day.