Thanks all! I wanted to ride this morning before the LBS's opened, is why I didn't go right to them.

For the record, it's the top pulley in an '07 Ultegra derailleur; both the "race" (is that the proper term when it's bushings?) and the inner bushing are ceramic. There didn't seem to have been grease in it; it cleaned up really nice with Simple Green and water and running a damp paper towel through it a couple of times. Just a bit of oiliness, which maybe could have migrated from outside, even though there is kind of a seal over the assembly (very light flexible plastic channels that set into the grooves on either side of the jockey wheel, with metal covers that cup to fit inside the channels).

Shimano's very helpful Technical Service Instructions say to "lubricate all moving parts" and "we highly recommend Shimano lubricants."

Park Tool's website has a discussion of ceramic ball bearings (pictured in a hub IIRC), which they recommend packing in the same grease as metal ball bearings, but that's obviously not the same thing.

After searching generally, DH (former professional motorcycle mechanic with no b/c experience) advised putting it together with just a dab of engine oil, which is what I did so that I could get in my ride this morning.

I did put threadlocker on the fasteners since they'd had some before.

A call to the LBS is on the agenda for this afternoon, to find out if I need to take everything apart and re-do it!