I just saw the same thing today. I took the plug boots off to see if there was water in them. Instead I found oil. It was just at the top of the boot. There was enough there to drip.
I was looking in the first place because the car(2004 Impreza) just went through a flooded street, and now it does not run. It turns over, and will run for small bits of time, but acts like a cylinder isn't firing. If I put it in gear it dies.