Pocketnow says that the Nokia Lumia 900 with ATT LTE is at the FCC for approval. It also states that the 1700 band used for LTE may also be able able to carry HSPA* on that band as well opening the door for TmO as well.
Supposedly noy in my area until sometime late 2012 or first half of 2013. Nice to have but not if Apollo backwards compatability is still in doubt. They need to clear that up nobody is going to want to buy a current device on contract and be without Apollo updated device for a year to a year and a half.