These two cameras are pretty much a draw. Personally, I think that I prefer the feel of the Oly in my hands -- but I would also say that the Panny feels smaller in size so probably more portable. The Panny seems faster than the Oly -- but I have only spent a couple of minutes looking at them both.
I would also say that from what I have seen the Oly jpg output is better than the Panny out-of-the-camera without any tweaks.
Olympus e-620 / 14-42mm / 40-150mm
Metz 48 AF-1
Kata 3-N-1 20, LowePro Orion Mini, LowePro Nova 2