There was always a good chance that the Sony Xperia Z1 would be picked up by T-Mobile in the US, especially since it was the only carrier to offer the Xperia Z with appropriate LTE bands. Well it looks like T-Mobile will also offer the Xperia Z1, judging by the leaked press pic courtesy of @evleaks.
This is likely to mean that if you were hopeful of Sony Mobile releasing an unlocked Xperia Z1 (C6906) with LTE bands compatible for the US market, you’ll be out of luck. We understand that Sony will still release an unlocked version of the Xperia Z1 in the US at some point, although this will be the HSPA+ model (C6902). If you want the LTE model, however, you’ll have to go through T-Mobile.