Scientific Publishing in a Modern World: A Thought Experiment

Norbert and regular readers of this prestigious blog may have seen me participate in some discussions about open access publishing, e.g. in the wake of the Lingua exodus or after Norbert's link to that article purportedly listing a number of arguments in favor of traditional publishers. One thing that I find frustrating about this debate is that pretty much everybody who participates in it thinks of this issues as how the current publishing model can be reconciled with open access. That is a very limiting perspective, in my opinion, just like every company that has approached free/libre and open source software (aka FLOSS) with the mindset of a proprietary business model has failed in that domain or is currently failing (look at what happened to OpenOffice and MySQL after Oracle took control of the projects). In that spirit, I'd like to conduct a thought experiment: what would academic publishing look like if it didn't have decades of institutional cruft to carry around? Basically, if academic publishing hadn't existed until a few years ago, what kind of system would a bunch of technically-minded academics be hacking away on?