To be honest, I don't really think Apple cares about people that will be eligible or not eligible for an upgrade. They sell their devices for the $649 to all the carriers, and it's the carriers that choose to discount them for the 2-year contracts and guarantee your business (with data plans, et cetera) for the next 24 months.
There are always people "coming up" for an upgrade and always people "locked in" for a carrier contract.
I think they're going to launch it when it's ready, simple as that. Apple usually does tend to stick with a once-every-year timeline with any of their products - just look at the Macrumors Buying Guide history. But, was the 4S the oddball, or what?
I'm not sure I understand an October launch overall, since most of the kids are back in school and it's far enough away from the Holidays that you really wouldn't consider it a "Holiday Gift." Perhaps WWDC2012 would see the next launch, simply because it's a huge event, rather than the little whimper that was October this year.