sys-fs/fuse tries to merge the /dev/fuse device node, when it should be doing so directly on the root filesystem, or not at all. This is because some people may mount /var with the nodev mount option (usually a safe choice), making it impossible for them to ever emerge sys-fs/fuse properly. Creating device nodes is really the job of udev, not portage. I propose that the device node should either be created in the pkg_preinst phase (as is done in >=sys-fs/udev-090), or not at all (since fuse already installs a udev rule file for the device).
Also, I've been reminded that portage doesn't even unmerge device nodes at all (it never creates a VDB entry for them, so they'll never be unmerged). So, there really isn't any point in trying to have them merged along with everything else, anyways.
QA, could you fix this? genstef's devaway: away from gentoo for some days - feel free to fix my packages
last i checked you were a gentoo dev which means you could have fixed it yourself :P 2.6.0_rc3 no longer creates a device node