Yesterday I wiped the T case clean and will be keeping a close eye on the leak for the next few days. I'll also want to see if I can determine the fluid level in the T case, very much along the lines of what Kurt is saying. I am thinking that if it's a "stable" slow leak at about one drop every few days and there's plenty of fluid in the t case it may not be something that needs attention right away. If, on the other hand, the fluid level is low then it needs to be looked at.
I had the transmission serviced recently, but I don't think they touched the t case.
Edit: Went out and looked at the T case in daylight. It's obviously quite a bit dirtier than I thought last night but that's not the problem. I took a few photos and I *think* this might be where the leak is coming from:
-Simply because it's the highest point on the T case that is wet, and since fluid will run down, and not up, I would suspect this to be the point that leaks.