At this time there is no migration path for SEE v11 from Symantec Encryption Management Server. It is only for drive encryption as well, so if you are using any other features of the SEMS, they would not be available in the new product.
It is a common misconception which I believe is based upon using too similar of a naming scheme, but SEE v11 is not the next iteration of Symantec Encryption Management Server/Symantec Encryption Desktop. It is a drive-encryption-based combination of our Endpoint Encryption and Drive Encryption (PGP) softwares, basically combining the best features from each drive encryption product into a single product.
In short, you would need to be using whole disk encryption only, and be willing to decrypt any existing systems, uninstall the current PGP product, install and configure a management server for SEE v11, generate and deploy new client packages, and encrypt the systems again.