One of my local shops (Empire Games in Mesa, AZ) is running a map based campaign/escalation league for the next couple months. The map updates weekly on Sunday as a result of battles that take place over the course of the week. I'm playing for the Xenos team, and there are also Imperial, Marines, and Chaos teams... and the one Tyranid player is all by himself. So far it looks pretty awesome, and I've participated in two battles as of this post.