Yes, it should be interesting to see what effect this has on marketshare. I recall that in the months leading up the iPhone 4's release, all of the talk was that Android's advances were only temporary, all just waiting for the iPhone 4. Of course that turned out to be utter bunk. So then everyone moved onto the Verizon ruse.
People dedicated to getting an iPhone have long moved to AT&T (which paid off handsomely for AT&T, which is why they paid heavily for exclusivity). For all of the anti-AT&T chatter, in most empirical tests it has a faster network, it uses global bands, and it has better support. Now instead people are supposed to rush to a company with worse support, slower real world speeds, a network that works on one provider in one country on the planet, and no simultaneous data and voice, to get a phone to be replaced in mere months?
Give me a break. In two months you and others breathing the same nonsense will have to somehow find some new spin. Ah yes -- it's just the calm before the iPhone 5 storm!
Note also that AT&T, in losing their exclusivity, is suddenly becoming far less enamored with the iPhone. Not only are they getting some premiere devices like the Atrix, they're actually starting to promote them. They might even stop gimping them quite as much.
This is big news for a couple of days because it was so anticipated for so long. Yet it really is too-little, too-late. If Apple makes a killer iPhone5, which is entirely possible, then the game changes, but for this it's just the pent up nature that has so much hoopla. Once people sober up I think the reality will set in.