cool, I think you will be amazed at how much better the raw of that shot looks anyway 
do you have a fast aperture lens? a nifty fifty or know someone who does so you can try it out very wide open?
thats where i am finding mine goes all haywire at relatively narrow apertures its ok but go wide and everything goes to hell. and i'm not even pushing the lenses right down to f1.4 (which they preform perfectly at on all my other cameras) even stopped down to f2 or f2.8 they are miss focusing bigtime.
Believe me i'm not taking the camera back because of a few bad shots. I have spent a massive amount of time troubleshooting this and I am certain the problem lies in the AF on my copy (however it seems lots of people are getting good results, I just suggest you check it thoroughly while you are still in a window you can return it if you do find problems a $100 50mm f1.8 will show up any wide aperture focusing issues if they are there.
Hey Wickid, firstly, I appreciate all the testing you have done and reported back here. When I tried to reproduce your work, it confirmed to me that I had a good (or better) copy.
I just checked mine using the 50/f1.8 at 1.8, 2.0, 2.8, 4.0, 5.6, 8.0, 16.0 and found all focused really quickly and sharp on an ISO12233 chart. I used single point focus on the centre of the chart, tripod, remote release and mirror lockup to make sure I didn't disrupt the focus or create camera shake myself.
Now as you can see, this is VERY controlled conditions, and I haven't tried it in real world conditions at lower than f5.6 (and that was sharp), but this gives me great confidence going forward.