I played aroud for a short while and was not that impressed. First the camera is trying hard to be like a Leica - which is not necessary, really. To mimicking Leica, the camera is oversized for what it can be, I think it would be a better camera if it is smaller, but bigger than X-100. The technology will allow the X Pro-1 be smaller, but I think Fuji follow something wrong. HIstorically Leica M arrived at the size through slow development, there are pre M3 Leica that are smaller, and M3 and the following models arrived at a size due to many factors, many were mechnical factors, so Leica was all along trying to be simple, efficient, and elegant, and then they became Leica.
What Fuji did was Leica the Konica, they try to be Leica, rather than staying simple, elegant and efficient (in use). I think Japanese maker needs to be something of their own DNA.
Image quality? Really I am not that concern, not because I don't care the quality but I think into 2012 all the cameras of this level will perform rather well, I am more interested at NEX7 or a bigger camera like D800 or coming 5DX or even bigger pro models because I am already accustomed to them and have range of lenses available.
Final note, I think the exterior of Pro-1 was rather emptied not that I don't like simple but Fuji seemed to have hard time getting all the function onto the camera in a more balanced way, the camera looks missing something. The viewfinder is a mess to me, I am rather confused on how it work and how to indeed focused, may be it is just me, but this is considered the 3rd model from Fuji on this X series, it is not a great camera to use for me.