LJ, I don't think bookstores will be around long enough for a new model to emerge--I think there's less than a 5-year window to have a viable distribution below the bestsellers (who I suspect will thrive in paper for probably a decade or two longer). Here's some illuminating articles, and I am not sure the "middle" will exist anymore. Though we are doing something similar to what you propose through Haunted Computer Books, small publishers may not offer enough to make up for the cut they will be taking.
http://www.publishersweekly.com/pw/b...ublishing.html
http://www.publishersweekly.com/pw/b...g-options.html
Scott