Xcode 4.6.1 crashes whenever i try to add my device to the provisioning portal through Xcode Organizer.
Here's the solution:
Run the following commands in Terminal:
mkdir ~/Library/Developer/Xcode/OldPortalDBs; mv
~/Library/Developer/Xcode/connect1.apple.com* ~/Library/Developer/Xcode/OldPortalDBs
Start Xcode and try again!
For more details, see the official post on Apple Developer Forums.