From second day sessions' recap:

Hurd: Janneke Nieuwenhuizen led a discussion around GNU Hurd, which is
a microkernel-based architecture.  Activity has increased in the last
couple of years, and there's support for SMP and 64-bit (x86) is work
in progress.  There's lots of ideas and excitement about getting Guix
to work on Hurd.

The full notes mentions a group of sixteen people attended.