Indium sounds spiffy and optical computing doesn't sound so shabby either. I have a feeling they're hitting their limits. As it is, there really haven't been any major improvements. Not like there were back in the days of moving from a pentium to p2. I think there's even a struggle right now getting the die's shrunk (which is why the next release isn't scheduled until 3rd or 4th quarter 2015).
Another issue is already presenting itself. Unless I'm wrong, the reason people aren't getting superclocks out of overclocking even the unlocked cpu's is again due to die size. They've increased the amount of transistors, shrunk the package and managed to reduce thermals - but because there are so many transistors in smaller space, heat goes up faster with overclocks than it did on larger processes. Pretty soon overclocking room will be tighter and tighter and that's not very exciting (to me personally anyway).
There also seems to be issues for the gpu manufacturers which is why they've been stuck on rehashing the same die sizes even though they've managed to optimize what they have. I read an article talking about shrinking the die process and how it needs to cost less per chip with a die shrink and when it comes to gpu's it's actually costing a lot more. Preventing progress on that front for now.