The value in this sort of compromise is that it's relatively painless to existing systems. You won't need to explain a whole new peer review system to a tenure committee, you won't need to radically restructure your grant spending, libraries pay more or less the same costs, and the journals get more or less the same revenue. The only difference is that now, your results are free for everyone to read (and not just in preprint form).

We'll have to wait and see whether this model turns out to be the first step in a gradual transition or a stopgap solution until a radically different approach to peer review becomes accepted. I for one am excited to find out.