The author who wrote the book on the Obamas is not an Anti-Obama guy at all and this just fit into the story he was telling when the Obamas were having $$$ issues. Apparently Obama could not finish his book and had already spent the advance. Michelle called their friend Ayeres to help Obama finish the book since they were good friends, or so the author claims. The author said that he had relatives as sources and I think Michelles' mother was talking to the author. This is a tiny part of the book overall, but it stunned a lot of people since it completely opened the pandoras box on this again.
The guy named Cashill is the one Al was referring to. He did some kind of test on the text and said it replicates almost the same as Bill Ayeres' in his books.
This book just came out and I am sure that we will learn more as time goes on.
Cashill didn't perform a computer text, he read samples of each guy's writing and claimed he could spot the similarities between them.
The book has no other named sources in regards to this theory besides Cashill. As a matter of fact, even though Cashill previously only maintained that he suspected the book was written by Ayers because of writing comparisons, in the book he goes into unverified detail about the behind-the-scenes making of the book.
The guy who wrote the book has written dozens of tabloid-style books and it's pretty obvious that most of them are just rumors that have been floating around for awhile compiled into book form.