It doesn't affect me since I only have one dock and I'm sure there will be an adapter.
That said... the idea that apple is never ever allowed to change their jack design is asinine. We'd still be on a fuckin' serial port for a mouse and huge 5-Pin Keyboard jack on desktop systems, with that kind of thinking. (XT->486 era tech)
Apple aims for thinner / smaller all the time. A smaller jack potentially means more real estate for a battery, or whatever that small extra bit of real estate can be used for. It may not seem like much, for just a connector jack, but in engineering, every little bit counts... and that is probably not the only thing getting shrunk in the guts of the phone.
I wish it was the standard USB mini jack that you find on cameras... but there's no doubt it will be proprietary.