It's 12:30 a.m. and I just got back from my 24 hour convenient store with their only copy of DQXI. I live in a well-populated area just outside of Chicago so I'm a little concerned that they only had one copy.
It just finished installing and I'm about to play. I'll post my thoughts tomorrow. Also, for those that were complaining about the American box art being a watered down version of Toriyama's artwork, I want to point out that the sleeve is reversible and has the Japanese version on the back.
The day one patch is about 10 GB.