Take a look at this post on Little Green Footballs. I am no expert (in fact, I know nothing about authentication of documents), but I cannot imagine how the obvious defects in the documents here can be explained in any other way than as a forgery.
Keep watching this one, folks.
UPDATE TO THIS UPDATE: Hugh Hewitt produces this roundup of information on this story, as of 2:45 p.m. Pacific time. It just gets "curiouser and curiouser."