Recently, Fantagraphics became the first major "alternative" publisher to sign with Diamond.
Diamond has a monopoly. But because it is in a niche industry, it is not likely to attract the attention of attorneys general unless there is an organized stink.
A revolt could happen. Fantagraphics leaves other alternative publishers, like Drawn and Quarterly, weakened, because they are now outside the monopoly and have seen an ally defect. Vocal artists, frustrated with the impossible terms of getting short run, independent efforts onto comic store shelves, might become vocal. Or, potentially more troublesome, they might take Diamond to task in their own medium. As Boss Tweed said, "Stop them damn pictures!"
Diamond might do well to organize a special project in which a certain number of slots are allotted at favorable rates to those who would not otherwise do well under Diamond's terms. It could be a cooperative project run between some comics people and a Diamond rep, with the understanding that Diamond would promote the work intensely. Co-branding could even be considered, such as "Diamond-Indy." Proposed participants could be vetted by a small committee so the project wasn't undermined by inferior work.
A publisher with favorable rates with Diamond, such as Fantagraphics, might arrange piggy-back printing to help control that cost and protect themselves in the event of a regulatory assault on Diamond's market control. It's in their interest to see a little more competition, if they like their cozy relationship with Diamond. Fantagraphics chiefs don't have a good track record when it comes to respecting web comics, so they might not be the best choice. Marvel, with more at stake, probably couldn't produce the right personnel. You quickly see that assembling even a small committee would be burdensome, but if independents realize the leverage they have given Diamond's legal position, they could almost appoint the whole team.
Web artists hoping to extend into print might open a forum site to measure interest in organizing. It might fall prey to the same forum toadstools that sprout at just about every similar venue, but sometimes real leaders emerge, even among artists.
Todd Allen's book, The Economics of Web Comics, 2nd Edition, contains chapters on Diamond and the economics of print distribution that are essential to the discussion.
Please consider this a thought piece, and not advocacy. Internet outage in our area has forced a rushed completion to host it today, and I will certainly revisit it more thoroughly in the future.