Panel: When will the cost of dependability end innovation in computer design?

As silicon feature sizes approach atomic scales, device reliability is waning and the cost of dependability is on the rise. Post silicon devices, such as CNTs or TFETs, promise better performance but at the cost of even worse reliability. Will we reach the point where the cost of reliability for future silicon substrates is too expensive to justify their existence? Or will we discover new ways to contain the cost of dependability? If we do discover low-cost reliability mechanisms, how much time do we have before we must deploy them? If not, how much life does silicon have left?