initial thoughts on the GH3 (or, holy cow, this camera is good)…

From what I've seen with the GH3, IQ is good, with the XE-1, IQ is great, on a whole other level.  I have an X-Pro1, D800, and GH2.  And shooting the same subjects with the GH2 and X-Pro1, it's dramatic how much better the X-Pro1 images are.  They are cleaner at base ISO, high ISO ability is no contest, significantly better colors from the Fuji (even better than the D800), better sharpness and fine detail likely due to no AA filter, absolutely no mushiness like some GH2 files tend to exhibit.

On the other hand, the video quality is the superb from the GH3. I will say you can get similar (some say better with less aliasing and moire) with a hacked GH2, but that's a whole other subject.

One nice thing about the Fujinon lenses (other than the fact that they as excellent lenses, all of them) is because of the aperture ring, you can easily use them on m43.  I say an Fuji X to m43 on the JJC the other day, and I'm definitely going to order it so I can use my favorite lens, the XF 35 1.4 R, on my GH2.