The guy isn't your typical CEO material, but that much is obvious. He's a coder, a simple guy that had an idea and went with it. In truth, his idea wasn't particularly brilliant or revolutionary; rather, just a simple idea that caught on (much more than his competition) and grew to what it is now. That success, and all the intarweb market share that goes along with it, is why he garners attention, not because he looks good in a $2k suit and can rival politicians with his doublespeak.
So, I highly doubt that MSFT or anyone else will devalue him or Facebook as a result of the interview.