Tim - the answer is both and neither and more confusing yet. Let me explain:
a) SET is only supported when the SDN-extension is installed in the Hyper-V switch.
b) SET works with Live Migration, as does SMB (as shown in the figure).
c) Live Migration is not supported when the SDN-Extension is installed for TP3 only. Expect this to change in future previews.
Summary: As a result of A and C, Live Migration is not supported with SET in TP3.
Don Stanwyck, Sr. PM, Windows Server Networking, Microsoft