Verizon has confirmed to CNET that it will be requiring all future smartphones to support 4G LTE. The carrier revealed that it would be an unyielding requirement for all upcoming 2012 mobile devices if they wish to run on Verizon's network. This includes smartphones, tablets, and even mobile hotspots and netbooks.
It seems pretty certain that we'll finally see a 4G LTE iPhone 5 this year and we've already seen two LTE-capable Windows Phones. The HTC Titan II and the Nokia Lumia 900, both LTE-capable, were just announced for AT&T. Verizon so far carries only one Windows Phone, the HTC Trophy, and had given Microsoft an ultimatum last month demanding LTE devices only.
Despite this, Verizon's associate director of device marketing Keith Lampron expressed that the company does intend to fully support Windows Phones in the future, suggesting some LTE Windows Phone models for Verizon are in the pipeline.