I borrowed this link from my friend, Rachel, who had it posted on Facebook. (Hope you don't mind, Rach, but this was such a good post. It's entitled When Anyone Can Be a Published Author and is all about the future direction of publishing. You can check it out at: http://www.salon.com/books/laura_miller/2010/06/22/slush. (Forgive the lack of highlight - for some reason, the link feature isn't working on Blogger.)
With the rise in self-publishing going on, I predict a new type of Gatekeeper will emerge - the readers, themselves. Readers will resent spending money on inferior work. They'll start to take notice of the established publishing houses, both large and small. If they run into a publisher they don't recognize (because the self-published author has created a fake publishing house, for example), they'll think twice before buying a book.
I don't worry that established agents, editors, and publishers might be replaced. They won't be; there will always be a place for them and even more so, in the future. It may, however, take another ten years for readers to become astute.