LinuxMCE's architecture allows for far more than ZoneMinder could ever do, but it would be interesting to attach ZoneMinder as a DCE device, to send data to and fro...
now of course, Orbiter needs to be dealt with in regards to UI, please keep in mind that this system isn't duct taped together.. it is very finely integrated, and all decisions regarding which applications to bring into the fold must take this into mind.
-Thom