I haven't been able to find any pre-order sites either, but I'm hoping when, and if, one of us discovers it, he/she will will be sure to remember to post it on this thread, so we can get in line.
I been wanting this since they announced it at CES in January, and the reviews since have not discouraged me. This one has been flying under the radar up til now, with little promotion or coverage, and I really think sales and user reaction will shock the industry, once it hits the field.
One point I'm not clear on is if the 32gb version, and the keyboard/dock will be available with the initial release.