Just wanted to note that I was checking the transmission in my 2004 WRX while I was changing the oil. The transmission body felt like there was a thin layer of gear oil on the outside. It certainly smelled like gear oil. There were no apparent leaks/drips. I seem to recall the body was like this when I first checked out the transmission (before I changed the gear oil at 3800 miles with Redline 75W90NS).
When I changed the gear oil, I wasn't able to replace the transmission drain bolt gasket, and simply turned it over and hoped that it wouldn't leak until the next gear oil change. It's definitely not leaking around the drain bolt, and the gear oil level hasn't dropped on the dipstick. I was at the dealer yesterday, and bought a new copper gasket ($2.80) for my next change. It has a 30mm inner diameter, is 2mm wide and 3mm thick. I understand previous Subaru transmission bolts would take the same 18mm inner diameter crush washers for the oil drain bolt.