I assume your datacenters are 2 different sites.
I think unless your VM is too large to move the data across your network connection in a reasonable amount of time, there isn't a need to move the physical host.
There might be other alternatives:
- a) if your vSphere environment is 5.1 or greater (you only mentioned "vCenter5") and if you have the appropriate license, vSphere Replication can be used to create a clone of the VM between 2 datacenters. Some manual work could be required to complete the migration with this method, though.
- b) power off and deregister the VM from the first datacenter, then manually transfer the files via SCP, SFTP etc. over to the other datacenter and then it add it to the inventory of the second vCenter.
Keep in mind that whatever method you choose, network settings will have to be properly adjusted. Traffic will have to be rerouted and the VM's gateway will have to be changed.