We've been hearing rumors for a while about a WiMAX-enabled smartphone coming to Sprint sometime in the near future. Now, thanks to Mark Sullivan of PC World those rumors just got a boost of support. He spoke to a series of wireless carriers, handset manufacturers, and market analysts and now believes that a 4G smartphone on the Sprint network is coming.

WiMax is basically mobile broadband, and it allows a connection three to five times as fast as traditional 3G. Since Sprint owns 51% of Clearwire, the WiMax carrier, they have a vested interest in setting off a consumer craze for the service. Sullivan thinks an Android smartphone would be the perfect choice for Sprint's flagship 4G phone.

This new smartphone will be dual-band, which means it will contain a 4G and 3G radio, so that you'll be able to switch between either. If WiMax is not available in your area but 3G is, you won't lose your coverage. According to Todd Rowley, VP of Sprint's 4G business, they'll be ready to roll out a handset when the Clearwire WiMax network hits 100 million customers. That is set to happen in "late 2010".

Both Sprint and Verizon have 4G networks under development and plans for 4G releases in 2010. It remains to be seen which carrier will beat the other to the punch. If certain iTablet rumors prove true, Verizon could be offering 4G support for that in early 2010. There's no telling how accurate or inaccurate those rumors are, but we should have a better idea by the end of 09.