Assange could fake that document. The information would be 100% bogus -- but if the document were released through Wikileaks, people would buy it and the Obama's administration would fall virtually overnight. An easy way to take him out.
I posted my comment above before seeing your speculation on a Wikileaks cable implicating Obama in suppressing Kenyan revelations about his birth.
You've been reading too many Clancy novels! On the other hand, Assange and his confreres are just the sorts to do this kind of thing!
So, we'll sit back and wait to see just how far the Wikileaks mischief runs.