Awhile back I found the water pump/seal leak threads because I had some fluid coming out of the witness hole. But I haven't seen this come up here after a fair amount of searching...
New '09 purchased May '10. Around 3k miles taken to dealer for fluid coming from water pump witness hole. Appeared to be oil (no sweet taste, thicker than coolant) but note that the coolant overflow tube dumps out there and it's possible both coolant and oil can come from the witness hole.
Dealer pulls water pump and checks. Says it's just the coolant seal and replaces under warranty.
500 miles later same symptoms. This time i get the dealer to agree with me that there's definitely oil coming from the witness hole before I leave.
Pitted balancer shaft. I haven't done low end work but the shop manual says they'll be splitting the case.
I didn't post to cause undue worry but more to note that if do get oil from that area you may want to tell your mech about it so they'll inspect. It could just be a seal etc. From what I found online it's far more common to get a coolant leak there indicating a water pump seal issue, which is likely why my shop leaned in that direction first.
The witness hole is where the water pump is attached to the engine. I normally just eyeball it (like everything else) when I'm doing an oil change.