Well, maybe this could work, but probably it would have to replicate the "coercive" component of the current system. In other words, by reviewing other people's papers you somehow improve the chances of having your own papers reviewed. And if somehow that system manages to also provide an incentive to do the job thoroughly, then that would be a huge improvement on top of what we have now.
Well, the coercive component is the unified reputation that you gain in this site, just like the reputation that you gain in SO. Obviously, the higher reputation you have, the more recognizable you are and more people read about what you do.
