I have just read a fascinating editorial by Tony Pollard and Iain Banks in the new Journal of Conflict Archaeology about the need to excavate concentration camps as part of military archaeology. As survivors die, and camps fall apart, there has to be a record of the physical remains of the Holocaust to prevent propagandists such as David Irving gaining the upper hand.
We tend to think of archaeology as something that deals with the distant past, but it can also clarify the recent past - particularly claims and counter-claims made by different sides during a war.
Another recent WWII excavation, in the States (which I am glad I was not involved with, given the finds were radioactive):
US nuclear relic found in bottle - BBC