>More depressing -number of cores will also level off eventually and where does that leave us then?

Short of breakthroughs (e.g. quantum and currently unknowns), the only clear path is less generalized architectures and more specialized chips. As you move more towards ASICs from general architectures you get improved performance, reduced power, and so on.

We've lived in the era of software where hardware was abundant and cheaper than an engineers time. Throw more hardware at it and make sure you have generally optimal algorithms in most your run paths. That's going to change more and more and I suspect we're going to have to start rethinking or redeveloping some layers of abstraction between current software and hardware.

As it stands now we're building more and more complex things atop weaker intermediary layers of abstraction to save time and meet budgets but that's going to have to be revisited in the future and the inefficiency debts we've been building up will need to be paid down. Clear code will become less of a top priority when clever optimizations can be added in that may not be so clear. We're still many many year away from this but that's my prediction.