According to an Apple source, they have begun testing iOS 6.0.1 with its carrier partners in the U.S. in preparation for a release in a few weeks. The update reportedly will address some of the issues users have been experiencing with the new software.
iOS 6.0.1 should fix both the horizontal flickering lines bug on the keyboard in portrait mode reported by some iPhone 5 users and the issue with the camera flash not going off consistently. No mention of the purple halo issue with the iPhone 5 was made, however, so apparently Apple is still claiming that particular issue is due to how users are framing their photos.
In addition to addressing those bugs, the updated iOS will improve WiFi support, fix cellular data issues, add a consolidated cellular data switch for iTunes Match, fix the bug that allows Passbook details to be viewed from the lock screen, and correct the issue that was causing some Exchange meetings to be unexpectedly cancelled for the entire calendar invite group.
iOS 6.1 does not appear to be imminent, though, as Apple is reportedly only just beginning to test it, so it is highly unlikely that the rumored upcoming iPad Mini will ship with iOS 6.1 installed. It is expected to come after the holidays, but it is still unclear what will be updated.