It is important to notice that on iOS6, several things have changed, among them:
1. The way Autorotation works has completely changed, delegating the screen orientation control to the top level window instead of a pre-configured parameter, in a way that orientation control can change during execution time.
2. Several changes on the ScrollView.
3. As Maps engine has changed from GMaps, it is important to test everything related to Maps and Geolocation on Ti running on iOS 6, even though Apple kept Map Kit API compatibility, some new things were introduced.
and much more...
Support for the new Statusbar customisations and the Passbook API is a very good thing to have.
I urge developers of Appcelerator to always keep looking the iOS6 release notes, even as it is in Beta as it will be available to final users in 2 months. As iOS users have a strong tendency to always upgrade, we need to have Ti working ASAP in order to keep our apps working on the verge of a new iOS release.