After a spot check and thinking it was a sticky caliper (rotor was warped in a very strange manner, 3 levels, inside was fine, middle was a step down, outside was...interesting. Figured the piston was bad) -- wrong, bad hub.
More importantly was how/what lead to this hubs failure. We dismantled the rear pass. side when doing a diff swap some time ago. When it was put back together, an impact was used (and for the record, I HATE impacts) to put the nut back on the 1/2 shaft and this, in turn, caused the problem.
The nut was seemingly secured properly (500ft/lb impact, but not on full), however, in doing so, we assume it loosened a lot of the rust in that area and this give it room to move and loosen itself slightly allowing the hub to become mobile, wearing the bearing down in a strange manner and effectively, destorying the hub and bearing.
Anyway, thought I'd share. I'd recommend going BACK a few days later and checking that nut. Amazingly, my car rides a lot nicer now