Expand on the idea. How would users interact with each other? Would they control the same cursor? Is everyone in one simulation? Can a user make a private group with an password? What happens if theres a difference in frame rate? Would the information be sent every time a pixel is drawn? Every second? Would there be a chat feature so users can communicate?
Be thorough when suggesting something this big.
Maybe Zones, NPC's, Only 1 Display, And Sorta Like An MMO