KeyPilot,
I was there in 2001 and the Navy Seals were over doing training... I haven't seen/heard of any US presence since then.
I was back again in 2003 and noticed a bunch of Paras training with the TA (never asked why, couldn't be bothered) there were also a bunch of Gr7s mucking about for a day then they disapeared, other than that it's pretty dead!
I do miss the old Gaydon hangar
I paid the bunker a visit also, although there was nothing there at all apart from huge empty garage like bunkers.