Just got an E-PM2 on Saturday. I bought just the body as I wanted to try out my existing 4/3 lenses. My initial reaction is mixed.
The camera was a bit smaller than I'd thought and initially I had some concerns over handling such a small camera, especially with a relatively large 4/3 lens attached. Although it seems a bit mismatched, I was able to get used to it pretty quickly. I'm using the MMF-1 adapter, which seems quite sturdy.
I haven't had much time to use the camera but so far I find AF to be a bit slow. When photographing relatively stationary items, this isn't really a problem. However, I tried to photograph my son's 3rd grade basketball game and most of the photos were too out of focus to be useable. My previous E-520 did a much better job of capturing faster action.
I also noticed a bit of shutter lag. The camera's reaction seemed more like a point and shoot than a DSLR. Not sure if this is typical of mirrorless cameras or if this is related to using the 4/3 lenses.
One nice feature for sports/action is the sequential shooting. It's great in terms of the number of frames it can capture in a short period, which somewhat negates the slower shutter reaction. However I noticed that sequential shots and video take a long time to write to the memory card. This may be a function of the memory card and not the camera.
My initial impression of the camera is positive. It's nice to be able to use my existing lenses, but I think I need to try out some native MFT lenses to really gauge what the camera is capable of. I had hoped that this could replace my older DSLR but at least from my initial impressions, I would say that in terms of speed and size, there is something to be said for a true DSLR camera. I'm hoping that once I get to use some MFT lenses, my opinion may change.