In view of the sustained interest in new polymath projects, Tim Gowers, Gil Kalai, Michael Nielsen, and I have set up a new blog to propose, plan, and run these projects. This blog is not intended to hold a “monopoly” on the polymath enterprise, but to merely be a convenient central location for discussing and running such projects should one choose.
We have started the ball rolling on this blog with some proposed rules for running a polymath, a mock-up of what a research thread and a discussion thread for a project would look like, two new proposals for the next polymath project (deterministic location of primes, and a problem of Michael Boshernitzan), and a thread on how one should select the next project (which we intend to do in a few months, with a tentative plan to actually start the next project at around October or so). Please come give the blog a visit, and contribute your thoughts and suggestions, though it should be noted that we are not planning to start a new polymath project right away, but merely to plan for the next one for now.
[Update, July 28: Actually, this may change. There has already been enough progress on the "deterministic location of primes" project that a discussion thread and wiki page has been created, and this polymath project may in fact formally launch much sooner than anticipated, perhaps in a matter of weeks. However, much work still needs to be done in laying the groundwork of this project, in particular developing preparatory materials in the wiki and elsewhere to allow participants to get up to speed.]
On a somewhat related note, now that we have a dedicated blog for these sorts of polymath projects, I am thinking of revisiting the ratings system for comments that I recently turned on here. I guess this would be a good question to poll the readers on:
Note that the ratings system is somewhat customisable: see this wordpress page for details.