Feb 2011: Verizon iPhone CDMA.
June/July 2011: iPhone "5" with GSM/CDMA combo chip, works on AT&T or Verizon. The GSM chip will work with AT&T's newly 100% built out HSPA+ technology they call "4G" (which it isn't) and will promote that as their advantage.
June/July 2012: iPhone "6" with GSM/CDMA + LTE (ie. true 4G, with LTE networks on Verizon and AT&T supporting this technology)
I doubt that. Why go through the trouble of releasing CDMA only when you're going to release CDMA/GSM in a couple of months? Needless engineering waste. Either release CDMA/GSM immediately together or wait until LTE integration to do it.