Nobody knows, but if it makes you feel better, Verizon Wireless is 45% owned by a British company (Vodafone). The American half - Verizon Communications, which owns the other 55%, insisted on CDMA to maintain compatibility with their analog equipment. It's always been a point of contention between the partners, and I was very surprised Verizon Wireless never cut over to UMTS to help Vodafone for roaming reasons.
Whoa, random idea, and not likely to happen - what if the announcement tomorrow is that Verizon has been secretly building a UMTS overlay to their network and is ready to launch tomorrow with the current iPhone hardware - including the speeds and simultaneous data and voice? LOL, not going to happen - it'd have been found out by now - there's so many permitting issues with that type of overlay, but still, would make a nice "one more thing"