At a press conference in New York today, Sprint has announced that it will be launching an LTE network covering 800 and 1900MHz spectrum in addition to 1600MHz bandwidth in partnership with LightSquared (pending FCC approval in light of the GPS interference concerns). Sprint describes the deployment as "rapid" with the first markets expected to go live in mid-2012 and a full rollout in 2013. At that time, Sprint expects to cover 250 million Americans with LTE service - that compares to 120 million people in WiMAX markets today. The company believes that 1900MHz spectrum alone will take it through 2014; the addition of LightSquared would take it through 2015, and after that, they'd need to look at acquiring more to meet demand. Although iDEN is going away, LTE will be overlaid with CDMA - the CDMA network will remain a core part of Sprint's strategy for a long time to come.
As for devices, Sprint plans to release "15-plus" in 2012 that support the new technology. Handsets will span the range from low- to high-end and will be CDMA / LTE dual-mode; in addition, there'll be CDMA / WiMAX / LTE tri-mode data products (mobile hotspots, for instance).
On the WiMAX front, devices will continue to be sold through 2012, but by all accounts, Sprint appears to be going all-in on LTE. They're also looking at Wi-Fi offloading - not unlike what AT&T has done - which Sprint believes can alleviate roughly 20 percent of network congestion.