Nothing in those pics looked that fresh to me when I first viewed them. It was probably either from a leaking gasket that was replaced or a mess that was made when removing the valve cover or something along those lines.

I was convinced that my distributor o-ring was leaking just recently, the oil looked wet and more so than usual. I figured I'd just wait since I was installing a new dist. in the near future. After wiping off the area though, no further oil has shown up. I think it's just old oil residue from when the distributor was replaced years ago, maybe a recent car wash (w/ underbody spray) added to the wet look.