The initial batch of questions and answers at the Theoretical Computer Science Q&A forum seems promising. I encourage theoretical computer scientists to take a look, and to consider contributing.
The site has taken its initial cues from MathOverflow, targeting research-level questions in theoretical computer science. The public beta is planned to run for two more months. In the first two weeks nearly 700 people registered on the site, nearly 200 questions were posted, and nearly 500 answers were posted (with a lot of additional discussion and commentary). My initial reservations remain, but the experiment seems promising so far.
Several well-known researchers have participated so far, including Noam Nisan, David Eppstein, Ryan Williams, and more recently Lance Fortnow and Mihai Pătraşcu. Due to successful recruiting by some of the early members, the initial focus of the site is skewed towards computational complexity and algorithms, but I would like to see the broader theoretical computer science community being better represented. The way to achieve more questions about semantics of programming languages, automata theory, or logic, is to post questions in those fields, and to provide nice answers to such questions! I’m personally waiting for more answers about the historical roots of Milner’s bigraph calculus.
If the site maintains its momentum, it will also need a name. The early frontrunners are CSTheory, TheoryOverflow, and InfiniteStack. But more interesting than the name is the content, so if this sounds interesting, take a look: Theoretical Computer Science Q&A site.