http://blogs.regexadvice.com/ is really starting to pick up. I haven't posted there a lot myself, but looking at the latest batch of posts - people are really investing time and effort into writing useful stuff. And it's all regex centric.
As worthy of a community, there's even a big debate going on right now as to whether one should even use Regex to validate things such as email address or dates. You'd be surprised as to what the "gurus" think.
So - if you're at all interested in Regular expressions, much like SqlTeam.com weblogs is a great place for internal-hardcore data, so is http://blogs.regexadvice.com/ *starting* to be.
I do wish Darren took the time to start removing all those spam comments though...