Moore's law is based on number of transistors per chip. Generally this has equated to compute power at the same time. However, Moore's law ignores one higher level "law", the laws of physics. Electrons can only travel at near the speed of light, no faster. This prevents CPUs from talking to devices farther away as their speeds increase. With today's technology, it is rare to find any commercial CPU running faster than around 4Ghz, due to the fact that the next device it is talking to has to be within a few inches of the CPU itself.
Light (laser?) based computing will be no better.
What has to happen, to keep Moore's law alive, is to evolve to Bio/organic devices, which have much smaller sizes but high densities, like cell level. Also, building CPUs in cube format allows more devices within that magic distance from the CPU, so there are no delays due to propagation of electrical signals. Our brain is an organic computer, with a very high density, but not easy to program to specific tasks at high speeds, due mostly to the "human" interface.
So, to keep computing power doubling every period, like transistor count, we have to engineer electrical devices that have a higher density than what can be done with Silicon. Or, we have to change the laws of physics and increase the speed of light (at which electronic signals run very close at)...
Organic computing is a possibility. Just think of the power savings, when all you have to do is feed your organic computer a hotdog once in a while, instead of plugging it in...
"Resistance is futile" may come to reality some day...