Yes, they will, but they haven't specifically said when. My guess is after about a month like last year. Some posters on other threads are reporting that the "loophole" a lot of us, like me, used last year of buying an off-contract AT&T phone may not work as Apple stores might not be selling off-contract phones before the launch of the official unlocked version.
In Canada, they are selling the unlocked version for C$699, but only online and only to Canadian addresses (probably for the same reason).