I can't describe the noise any better than clicking, except to say that though it is constant, it does vary in intensity but not tied to driving over bumps, varying speed, or while making turns.
CV boots are all healthy and have grease in them.
No leakage at diff nor at hubs.
Only 'noise' we were able to reproduce was by moving the wheel back and forth, but I think that the 'clunk' it made (at the propshaft-->differential) is normal.
Doing a quick search, it seems as though some have had luck in tightening or replacing an axle nut, so I'm going to retorque them all.
A couple of things to note; I have some light, 17", Team Dynamics pro race 1 rims that I believe are a lower than stock offset (48 or 45 I think), and my suspension is stock. I imagine there's a chance that even though the rims are light, the larger diameter probably places a greater load on the hub bearings.
So, as far as troubleshooting goes, torquing all of the axle bolts is straightforward, but how do you identify if the wheel hub bearings are shot?