There's been a lot of activity on the L4-Hurd mailing list [1] lately. Looks like they are discussing [2] switching to a different microkernel, a derivative of EROS/Coyotos [3]. Especially interesting is the fact that Coyotos is implemented using a new specially designed language BitC [4]. After all, IIRC one of the major problems with the initial Hurd effort was the difficulty debugging multi-threaded translators written in C. A new language and recent research [5] might make the difference. Maybe a competitor [6] will spark renewed interest in secure modular operating systems.