From the "oh no, don't use something like MonoTouch, they take ages to update when Apple releases an update" files:
Continuing our long history of delivering same-day updates for device platform upgrades, MonoTouch 6 is available today and includes support for all of the new iOS 6 features that will be running on millions of devices before the day is through.
It's very similar - I'm told - to MonoTouch 5.4, but with iOS6 bindings. 5.4 has been rock solid, so go get 6.0 now!
Also, if you happen to be upgrading (as 6.0 requires a current license), feel free to use this link to the Xamarin store. You get 5% off, I get 5%. Works for new licenses too.