Too late. I've already tried to reinstall just MCE, which didn't work because pluto-dcerouter had unmet dependencies. More information on why I think that is happening is here: http://forum.linuxmce.com/index.php?topic=1532.0
One of my diskless clients has booted without the error but has been at a black screen for the last 5 minutes. Rebuilding the image for my Vista Orbiter yields the same error (see subject). Rebooting the core twice and nothing works.
Like I said, I'm pretty sure I hosed the core by not letting it complete its tasks from time to time. Next time I'll be sure to let it sit and do its thing before I do anything else.
If it happens again I'll be sure to procure the DCERouter.log file first.