"Well folks, it's finally here: the Sony Ericsson Xperia X1a. That's the US version with 3G HSDPA on the US AT&T bands. The Xperia is sold in the US at SonyStyle stores in silver and at Best Buy stores in black (Fry's, J&R and other retailers also offer the silver version). Don't confuse the Xperia X1a with the overseas version Xperia X1i (no "a" for America) that lacks all of AT&T's 3G bands."
Read on, US and Canada readers, if you're trying to decide whether to pick one up from a Sony store. I'll leave the details of the conclusion to the article, but in short, the author really likes this device. If anyone has picked up the Americas version and wants to comment on how well it works here, chime in the thread!