I had also spent about 2 hours yesterday with vmware support without any resolution, they did suggest if I could setup a new vcenter. Which I did today and I still received the error when trying to add the host. So after my last post above I looked at the error again(I think i have it memorized) anyways I did a esxcfg-mpath -l on the host and noticed I had multiple dead paths to the SAN. I did a rescan using the vsphere client and it got rid of all the dead paths but one. So I tried to add the host back to vcenter and it completed without errors. Looks like vcenter doesnt like more than one dead path showing on the host. Hope that helps
Next is migrating the vms off the hosts and do a reboot which I hope will clear the existing dead path.