Hot Chips, indeed
The major problem with cramming more transistors into chips is that if they all operate at the same time (which is a requirement for more performance), they will generate a lot of heat and consume a lot of power. The generated heat requires more cooling, which increases the power usage even more. There is a reason that your graphics card has a larger heat sink than your CPU, and the article talks about many more processing elements than on a GPU (albeit a bit simpler).
So rather than focusing on speed, the focus should be on power usage: Less power implies less heat implies less cooling. One option is to move away from silicon to other materials (superconductors, for example), but another is to use reversible gates: They can, in theory at least, use much less power than traditional irreversible gates such as AND and OR, and you can build fully capable processors using reversible gates. But even that requires a different technology: Small-feature CMOS uses more power in the wires than in the gates, so reducing the power of the gates does not help a lot. Maybe the solution is to go back to larger features (at the end of the Dennard scaling range).