You can choose to add a vmkernel port for management on vMotion switch and then add host vCenter with new address and migrate the VM's( this will need your uplink configured for vMotion to be able to send of the new network created).
http://kb.vmware.com/kb/1006989
The vm's if configured to be running on different network will continue to be up while you are working to fix the management network, any reason why you want to migrate VM's to other host?