I pre-ordered mine (yesterday), because:
1) I'd be getting it day 1 regardless
2) I want a physical copy
3) My local shop doesn't stock PC games standard, so I wanted to make sure they had a copy for me
I waited until now, because I wanted to make sure I had the system for it.
And I've played five Beth and/or Beth-engine games (MW, OB, SK, FO3, FO:NV), and they were all good and all ran for me when I got them. So I trust that I'll get a good game.