From what I hear there was no damage other than to the boom. It's not unheard of to land with the boom down. We have had it happen twice, once was because of a hydraulic failure, the other was after a combat support mission in the desert a boom operator from another unit who thought he was too good to even bring his checklist along on the flight forgot to put it back up before landing. Sad thing was that it was the second time in his career he had done the same thing. Even worse is that he was allowed to keep flying after the second one.
On a Kc-135 it's not that serious, you will get a little fire from the residual fuel left in the boom, but it only takes a couple of days to swap a boom out, and there are a ton of spare booms to be had. Now with the KC-767 I am guessing that there are not alot of spare booms laying around, so this plane will most likely be out of service for awhile.