The current hurd sources (available from anonymous CVS) produce a working hurd with the very current libc (with fixes I just checked in).
One gotcha (so far) for upgrading your gnu-0.2 installation to the new hurd: The translator /hurd/devport no longer exists. Its job is now filled by /hurd/storeio (which does so many other wonderful things too!). However, your /dev/time file will have /dev/devport set as its translator. This will cause some translators (e.g. nfs) to crash strangely. The fix is simple: `settrans /dev/time /hurd/storeio time'. (Or, use the new hurd's MAKEDEV: `cd /dev; ./MAKEDEV time', same thing.)
