T-Mobile to Speed-up HSPA+ to 42Mbps

"T-Mobile is announcing this evening that it's now got 75 live HSPA+ markets online, with coverage for roughly 200 million Americans up and running by the end of 2010. That footprint will start off at a theoretical max downlink of 21Mbps, but the carrier will be looking to scale that to 42Mbps in 2011 with the capacity to upgrade to 84 and 168Mbps down the road -- all without ever worrying about LTE"

I knew HSPA had growing room but man, 42Mbps this year with up to 168Mbp down the road is impressive.  Since current WiMax offerings I've heard of are only in the 5-20Mbps, HSPA+ sounds pretty good.  I am curious if many people would even use or notice the increased speed that current "4G" implementations offer.  Can you think of a situation where it would be valuable to you on a somewhat regular basis?  Would you be willing to pay extra for high speed service?  If you're using WiMax already, are you happy with it?  Is battery life a problem for you?