The project has been pretty slow to make progress but they do have a usable... if buggy system.
Pretty slow is an understatement considering its development started before Linux. I remember chuckling when, just a few years ago, Hurd finally got support for ext2 filesystems greater than 2GB. Maybe it'll turn around, but it never seems to have had the necessary momentum.
IMO, of the semi-obscure not-quite-Unix OSs, Plan9 is a much more interesting for its contributions (although getting it to run is a chore these days).