I'm trying to be economical with my posts, so you'll excuse me for two birds with one stone.
I agree, it's not quite up there with the K5 and the D7000 at high ISO . . . but it's quite close, and just for once it's nice to see a 4/3 sensor not drastically under performing (I've never been convinced by the excuses for 4/3 on the basis that the sensor is smaller), sure, it's cropped at the edges, but otherwise it's much too close for the size of an APSc sensor for that to be a limiting factor - it's the [email protected] sensors that Panasonic have come up with that are to blame!
So - having agreed that high ISO not as good as a K5/D7000 (but close), I'll go on to AF . . . I don't really use tracking focus, and I suspect that like everything outside Nikon it's not really very good . . .but, like lots of previous Olympus cameras the single shot AF seem very accurate, the difference between this and previous cameras is that it also seems very fast. This picture was taken by touching Sim's eye on the LCD - AF and capture was as good as instantaneous - and that's with the light assist turned off (does anyone really focus by flashing lights in people's eyes?!)