Officially vCloud Connector is the tool for this - however it may or may not work as you need.
One method that will take some setup (but might be worth it if you really need to move a bunch of stuff) -- would be create some scripts to do something like this:
vCenter1 - Clone VM you need moved
vCenter1 - Unregister VM
Move the VM to whatever the new storage is
vCenter2 - Register the VM
vCloud2 - Import VM (with Move option)
vCloud2 - Configure network ect on the VM/vApp
vCloud1 - Stop
vCloud2 - Start and validate
I know this is a simplification, but really the best way might just be export/import -- and at least VMware has a product to help wit that approach - vCC (vCloud Connector)