Regular readers will know that I do this a lot and have done so for years. Creating high-resolution files from m4/3 and other mirrorless cameras.
The files were shot in raw, processed in ACR vers.7.1 in the Photoshop CS6 Beta. Here's a few 100% blowups.
As you can see there's a lot of resolution and detail there, the image is pretty sharp and has no noise.
In comparison, here are three 100% blowups from a Nikon D800 sample, taken like the Olympus image at ISO 200.
At this level of "pixel-peeping" there is not a huge difference, and if presented with the same picture shot on the two cameras, I doubt that anyone could say which is which with any conviction. Certainly I don't think I could, and more to the point, neither could the people who sell or buy my pictures.
Obviously for many purposes its not possible to shoot 3,4 or more images and stitch them together later to produce a large high-res. image. However I present this because the D800 is being promoted as a high-quality Medium-Format equivalent camera suitable for landscape etc.
My point here is that, if you are working with static subjects, its perfectly possible and relatively easy to produce high-quality, high-resolution images with huge pixel counts on pretty much any decent camera. My four images took a relatively short time to stitch together using photomerge in Photoshop and a few minutes more to "straighten up" the resulting stitch and do some basic editing. The m4/3 camera / lens combination is lighter, smaller and cheaper than the D800 / 24-70mm f/2.8 combination used for the Nikon shot. The m4/3 shot(s) would also reproduce very large, as with the Nikon shot, and for publication or large scale-printing, again there would be very little perceived difference.
I do post similar items to this on a regular basis and will continue to do so. If like me you mainly shoot landscape, architecture and location material its a great way to produce very high-quality results from cameras and lenses that don't cost huge amounts of money and require a team of sherpas to carry them.