Book publishers see their role as gatekeepers shrink

Book publishers see their role as gatekeepers shrink - LA Times
Writers are bypassing the traditional route to bookstore shelves and self-publishing their works online. By selling directly to readers, authors get a larger slice of the sale price.

The article is partially correct. Yes, book publishers are seeing some authors go directly to an e-Book, giving the author a higher percentage of sales.

Sometimes this make sense, and sometimes not.
If your established and have a huge base of fans, it probably makes sense. If your not established and don't have a book publishing deal, it may make sense.  Its a lower cost than self publishing your own physical book with the required minimums (which is also changing with print on demand). If your in between, a book publisher offers editing and the ability to sell your product.

Charles Stross on his blog has some good posts on the economics of publishing.