I know the thread says US but I thought you might be interested in the UK position.
Currently there is no release date. Sony Stores are taking pre-orders saying:
'delivery will be within five days of release'
Waterstones, formerly a retailer of Sony readers, only has a discounted silver 650 for sale and no mention of the T1. They now appear to be concentrating on Elonex and Bookeen Cybook readers.
From that it's anyone's guess when they will be available here.