iOS 6.1 has been a curious update. It offers a minor handful of API upgrades for developers but otherwise has been a way for Apple to tweak internals. First appearing November 1st, the beta has had occasional updates, most recently moving to the fifth beta last night before its final release to the public.
Interestingly, the few API upgrades centered around Apple's troubled Maps API.
In any case, it's been a heck of a long time coming, and it's good to see the release finally make it out to the public. Especially since a lot of devs were worried that the beta would expire before going gold.
Other new features that are new to iOS 6.1:
LTE support for more carriers, with a complete list of supported carriers at www.apple.com/iphone/LTE/
