"We'll look towards LTE at the right point in time for us...That ecosystem is going to be much richer than the competing one from WiMax, which is really a niche play," said Neville Ray, Chief Network Officer for T-Mobile USA.
T-Mobile and Clearwire met recently, but nothing official came of it. Ray did say that they weren't completely ruling out WiMax, but his 'niche' comment now leads us to believe otherwise.
Neville went on to say that their HSPA+ network is already delivering speeds near those of current 4G networks: "We're not waiting for the technology choice, we have the right technology to deliver that experience today."
There is no word on when 4G will be available on T-Mobile. With WiMax from Sprint, and LTE from both Verizon and AT&T (in 2011), T-Mobile will have to add 4G service relatively soon to stay competitive.
source: Business Week via Electronista