It sounds like what I had. I was at a different shop for an oil change and they pointed out that the rear axle and PTO were leaking. I panicked, stressed, and worried about it, and made an appointment at an experienced dealer since I wanted them to do a custom alignment anyway (this one would do to your spec). I asked the tech about it and he said it wasn't leaking, just "weeping" I think, which is apparently normal and within spec, and Mazda corporate won't replace those parts under warranty.
Very clean, ZFZ!
I haven't done anything except drive her to work and home yesterday, I'm kind of enjoying taking the train in more these days and keeping the miles down. It also lets me read more, and I'm reading Alex Roy's (from Gumball 3000 fame) book, The Driver. It's actually pretty good, and an entertaining account of the Gumball as well as his personal reasons for entering and then taking the next step.