(warning: tangential)
"Knowing Apple, that sounds like a far more plausible explanation than the most popular theory I’ve heard: that Apple just wants to force iPad 1 owners to buy new iPads."
I totally believe this is true on the iPad front, but I can't imagine any other reason that iOS 6 would support the iPhone 3GS but not the 3rd generation iPod Touch. They have very nearly the exact same specifications, except one has a GSM radio in it and the other doesn't. I wouldn't mind if it didn't get further updates (three years is pretty decent update-wise), but the disparity is slightly irritating.