Hi,
As DVS setting are stored in vCenter server database, I dont think you will be able to migrate DVS settings to new vCenter server, unless you upgrade the existing vCenter 5.0 to 5.1.
So then you have to migrate the host back to standard switch and then move it to new vCenter server 5.1 standard switch. Once this is done, need to move it to DVS of new vCenter server.
Regards
Mohammed