On another thread, someone saw them in a Wal-Mart. http://www.mobileread.com/forums/showthread.php?t=56030
They aren't at my local Wal-Mart though. I was at Borders this weekend and they still had the 505 and 700 on display. I am also very anxious to see the actual 600, but don't get into town (one big enough to have anything more than Wal-Mart) that often.