Here's what had happened. In case someone finds their way to this thread by way of googling output shaft seal leak, I'll lay it out there.
I had the trans shop perplexed as he looked all over the transmission to find the cause of this leak. He ended up doing some research and found out the transfer case adapter, the little piece between the trans and T-Case went bad.
I have several theories about how this went bad, but I keep going back to when I was changing the exhaust and let the drivetrain drop pretty far and suddenly after pulling the skid plate. Then there's old age.
Anyway, irregardless, he found that if this piece goes bad it causes a vibe which will eventually cause the output shaft to wobble, in turn breaking the seal. The bad part is, they can no longer get this part from Jeep but managed to find one in their inventory.
They called me on Tuesday after taking it for a test drive and said I could come and get. I just them keep it overnight since the leak shows up after parking it. Wednesday evening tolls around and I pick it up. All dry so far, take the long way home and park it. Thursday morning all dry. I take it out Thursday evening and run it on the interstate. This morning, no leaks. It's looking up!
What I noticed is everything seems tighter. It seems to shift better and looking back I did notice a vibe, especially at idle. It was small but it was there. It seemed much smoother.
So unless something big happens when I get home this afternoon, we'll just say that adapter was the problem.