What interests me, though, is the demographic shift this will tend to have on any number of results. Landline use skews older and older each year, nevermind peoples' habits with the phone. I usually don't even answer my mobile unless I recognize the caller - if it's important, they can leave a message and I'll call back.
And I think things like that will end up driving polling behavior. They will have to adapt to the callback model, or offer people some form of payment to participate in a poll.
Longer term, I suspect the rules prohibiting auto dialers on cellphone lines will go away. IIRC, the nominal justification for that is based on the fact that cell phone users pay by the minute, so the time it takes for the pollster to connect has an actual financial impact. I suspect we are only a few years away from having unlimited talk and text become the norm.
What about SMS surveys? You might get better responses, especially if each respondent only get asked one or two questions.