Here's a piece in today's NYT about bloggers writing books. Why shouldn't a serious author begin with a blog? It proves to publishers that there are people who want to read your writing. Did you know Ana Marie Cox received a $275,000 advance for her first novel?
But maybe bloggers won't write good books. The Times found an assistant professor of new media studies to naysay: "The style of blog writing is more oriented towards short form one page, set in the moment ... The sense of immediacy is quite important in blogs."
So maybe all the magic will be gone if you saddle a blogger to a long project. I think it would be disconcerting just to have to write putting the new material on the bottom of the page instead of piling on top.