NZJJ, By adding the server to the vCenter and using vMotion to move everything over will work fine. One thing to be aware of is that by doing this will be pretty network and resource intense. In doing this I would recommend to set up 2 NICs as dedicated for vMotion between the hosts on their own subnet/network. If you can it would be even better to have that on its own switch all together.  If you have any questions or anything feel free to let me know and I would be happy to assist you as much as I can. 
Hi, We currently have a MD3000i with an attached MD1000. Attached to this are 3 Dell 2950's running VMware 4.1. We have just purchased 3 R620's and a MD3220 with an attached MD1220 (using SAS connections) To move the data across from the old SAN to the new SAN I was going to attach the new SAN to one of the R620's (running VMware 5) and then add this server to vCenter and then vMotion the VM's across to the new server and the data to the new SAN Is this the normal approach that should work ? Thanks, John  
Migrate from MD3000i to MD3220 (SAS)