Would they release CDMA iPhone 5 in June?
If yes, how would they deal with update issues?
If no, Verizon iPhone users would have to wait x months for new iPhone every year?
The way i see it, you just have to look what happened here in the UK when O2 lost exclusivity and Orange & Vodafone released the 3GS in January last year, they then got the iPhone 4 in June, the 3GS still sold lots, and you had the idiots that wanted the iPhone 4 5 months into their existing contracts buying the iPhone 4 at full retail or whatever. The precedent is there, this will not be any different.
Or the CDMA version will always come out 6 months later until a unified iPhone that works on all comes out.
Seriously, the US is not the only place where this situation has already happened, you yanks are just stuck in your little glass bubble and need to realise you're not the only people with the iPhone!