We will get a new Mass Effect game, that much we know. If it will be a prequel or if it's a sequel, that we don't know. Hell - maybe they'll just reset the clock, so to speak, and make a Mass Effect universe all without the Reaper threat? Kind of a Final Fantasy-style reconfiguration of Mass Effect DNA. Who knows? We sure don't, but it's fun to speculate.
What do you want? And what do you think we'll get?