Me, I'm a big fan of the Long Tail. Essentially, by reducing or eliminating up-front capital investment (specifically at this point via e-publication and print-on-demand), publishing can take a lot more risks with theme, content, material, etc. That immense flexibility comes with the elimination of economic reward. Quite literally a case of "it takes money to make money." Work on the Long Tail doesn't get widespread distribution or promotion.
Obvious problems exist here. We're generally conditioned to production quality. Go look at any book from a New York trade house and compare it to a local independent. You can almost always spot the difference at a glance. Different production processes, different philosophy of cover design, a whole number of subtle cues. As publishing never developed a significant punk aesthetic (unlike, say, recording), those differences in packaging quality affect reader choice. If you want punk publishing, the zine world awaits you.
E-zines don't have quite the same issue with design, largely because there's not a well establishing professional aesthetic there. Such as that does exist, it is easily replicable by a competent Web designer with some graphic arts skills, much more so than in print design.
Another issue is editorial proxy. One of the things you buy when you pick up Analog or an Ellen Datlow edited anthology is a group of stories selected by an editor you trust. A random anthology, or a novel from an unknown independent publisher, doesn't have that trusted branding. It has to work harder to win you over.
Likewise e-zines. Some brands have been established. SCI FICTION, discussed extensively in the Bloggasm article, was a megabrand on the scene. Strange Horizons is powerful. Jim Baen's Universe leverages a publisher's brand to attract and secure readers. Others are a shot in the dark, until you see a review you trust, or a writer you like appearing there.
Simon's point was economic, not editorial. I'm more interested in the editorial end myself, but then I am not a publisher. I can cheerfully disregard the economics, at least until my favored markets threaten to evaporate. Still, at the bottom, how do you monetize something that most people perceive to be free, that moves at relatively small volumes? And without monetization, the writers don't get paid. That I cannot cheerfully ignore. I work for free from time to time, but this is a professional career.
Interesting problems, obscure solutions.