Well this is pretty interesting now T-Mobile's HSPA + is projected to hit 42 Mbps next year and grant those aren't real world speeds. Real world speeds will still put it in competition with LTE speeds.
Possibly.
LTE's theoretical limit is up around 270mbps last time I looked.
But HSPA+ is not a huge upgrade for some existing UMTS carriers so they could beat LTE to market without a huge investment.
I'm sure AT&T was (and still is) torn on the whole choice between HSPA+ and LTE. Do you want to spend a little now to get a good improvement quickly, knowing that eventually LTE will be where all the action is, or do you hold onto your money and just go to LTE now?
It's a tough choice, and I suspect it's been made, un-made and re-made many times in many operators by now.
Same type of issue in VzW, where they had to decide if EVDO Rev B and/or CDMA Advanced 1X was something that would pay off for them, but there the chance to go with a more widespread (and cheaper) technology made the choice easier.