The International Telecommunication Union hasn't officially sanctioned 4G standards yet but chances are they will be based on OFDMA technology and they'll be Long Term Evolution (LTE), the migration path for W-CDMA, Ultra Mobile Broadband (UMB), CDMA2000's path, and an advanced form of WiMAX since WiMAX was officially sanctioned as a 3G technology.
Verizon Wireless nailed its stake in the ground, committing to LTE to align itself with partner Vodafone [1]. The operator's breakaway from its CDMA2000 path puts UMB in jeopardy since Sprint is committed to WiMAX. Since LTE is a 2009 story what type of momentum will WiMAX gain in the interim?
Related articles:
Nokia Siemens in joint LTE development with DoCoMo Report [2]
LTE could bridge Verizon wireless, wireline Report [3]
Links:
[1] http://www.fiercebroadbandwireless.com/story/verizon-says-it-backs-lte-whats-store-umb/2007-12-03
[2] http://www.fiercewireless.com/europe/story/nokia-siemens-joint-lte-development-docomo/2007-12-06
[3] http://www.fiercetelecom.com/story/lte-could-bridge-verizon-wireline-wireless/2007-12-04