This will be an interesting project to see how it takes flight... I can't honestly see publishers lining up for the rights to a new book that technically will have already been "published" but there are certainly enough ways of adding value that will make it worthwhile.
And as Scoble puts in, people who don't read the blogs will buy it to better understand it. The only issue? Timing. It needs to be out soon. Good luck Robert!
The Red Couch: Announcing a corporate blogging book: the Red Couch project