Thanks for the reply.
So basically it is for just using any 2nd telephone service I guess. I haven't ported my # yet so maybe I can find a use for it via GV.
That is what I did. After porting my GV number to Vestalink I got a new GV number and provisioned SP2 with it. I don't really need it, but it was interesting to do and there might come a time when it is useful, though it's life is likely very short unless Google changes its plans for GV.