Every time I reboot or halt, I notice there a failure at the point when it says 'remounting remaining filesystems read-only'. I think this only occurs when the system is booted up with an initrd (made by genkernel), where the mounting problem could lie at the mounted /tmp/.initrd/dev and possibly at /tmp/.initrd, even though that is not displayed in 'mount' output. Trivial to that output though, is that / seems to be mounted twice. This is a normal, ~x86 Gentoo system, with gentoo-dev-sources 2.6.1-r1. Genkernel version is 3.0.1_beta4.
Please read /usr/share/genkernel/README and note the section that says you must NOT have 'automount devfs at boot' checked. That will solve the issue you're seeing. Though the root doublemount I see as well but cannot figure out where that's coming from :/
