I'm planning continuing using the engineering sample Touch for development and haven't yet ordered a retail set. Is there an official word on whether this is a valid approach, i.e. will we be missing any features or engine support doing this or will there be some official period of support like with DK2?
Also curious to know if Touch devs will only get access to any free launch titles if they buy retail Touch controllers.
Not sure about all those questions. In terms of development, the retail Touch controllers are only slightly different than the dev prototypes, and most of the changes were cosmetic. The only real major difference is that the final version has better haptic response. Otherwise the buttons and features are the same. If haptics are important in your game, it may be worth getting a retail kit.