I haven't looked around really hard . . . but I haven't seen a webcomic, Youtube entrepreneur or anyone else do the most obvious slam-dunk eyeball magnet I can think of: The Apocalypse Now bit, starring a reasonable facsimile of Martin Sheen as Willard and, inevitably, a gross caricature of Charlie Sheen as Col. Kurtz.
Then again, when Charlie Sheen does the inevitable interview in which he shaves his head in the presence of a Serious News Reporter and then does a 6-minute monologue about a snail crawling on the edge of a straight razor, real life will once again overtake satire. Maybe somebody did the math and decided that it wasn't worth it to spend a week making a bit that won't be satirical anymore in ten days or so.