Yeah, I agree with you. I definitely think that next year they'll begin releasing for Verizon and AT&T at the same time. My gut is telling me, though, that this summer we'll see a very minor upgrade for the current iPhone 4 ONLY for AT&T (or possibly no upgrade at all. I know that it's expected of Apple to release a new iPhone yearly, but would it be that crazy if they showcased another one of their products at WWDC?)
Someone on this forum pointed out yesterday that the videos that were pulled from YouTube a few days ago showed the redesigned antenna band (which Verizon now has) AND a sim card slot. Obviously, the Verizon iPhone 4 doesn't have that slot, so I'm inclined to believe that the summer update will give AT&T the slightly revised band, and maybe a few spec bumps. (This would also allow Apple, and case manufacturers, to only worry about producing one type of case for the iPhone.
Then, in 2012, an LTE iPhone will be released at the same time for both Verizon and AT&T.
There's a very small part of me that realizes it's possible that Verizon may get an update this summer. But I'd like to believe that both Verizon and Apple wouldn't want to make their millions of new iPhone users that unhappy. Maybe that's just wishful thinking, though.