Interesting that Bellevue is implimenting this change, considering that a new regional dispatch agency is being created in Zone-1. The new agency will be called NORCOM and will essentially be what Valleycom is to Zone-3, although the agencies in the new NORCOM will have equal representation in the new agency.
Currently in the Valleycom configuration, the owner cities (Kent, Auburn, Tukwila, Renton, Federal Way) direct Valleycom's actions. Everybody else (the contract agencies) have no direct vote on issues, rather can only attempt to influence the owner cities. There has never really been any major issues between the owner cities and contract cities/agencies, but it is unequitable.
At any rate you can check out information about NORCOM at the following link:
http://www.ci.kirkland.wa.us/depart/CMO/NORCOM.htm