I've put together a set of test shots, at full resolution on flickr. These are taken with the Nikon D5100 plus 35mm f/1.8 lens in a a variety of situations, indoors and outdoors. Images are processed from raw using the levels and sharpening settings I would normally use for stock photography. All are hand held.
As can be seen there's some CA wide open and I haven't set up a profile in Photoshop ACR to compensate for this yet.
There's a review of the lens on Dpreview here.
I went out with the D5100 and just this lens yesterday, and as before was very impressed. While not as small as many of the other camera / one lens combinations I've used it is pretty light.
I took rather more pictures at f/1.8 than I would normally just to see how it worked. No issues with forward and back focusing, and pretty sharp wide open.
I'm actually quite surprised how much I enjoyed using this. Its certainly nice to have a shutter button thats so instant. The rather odd slightly delayed action of m4/3 cameras has almost become second nature to me now, and both my Leicas and Fuji X100 are somewhat different to the D5100, which is after all a standard DSLR response.
I'm able to change settings with the camera to my eye which I like, and overall the camera is a delight to use. All the advantages of a DSLR without the weight and bulk. Maybe I won't miss m4/3 and the X100 as much as I thought.