[matt2000]

Not in PCs, but I wonder if the iPhone would count as a largely custom designed computer. They do custom silicon for a lot of the system, and get much higher performance than commodity phones as a result. Perhaps the spiritual successor to these high end workstations in an odd way.

[pasabagi]

I think Linus mentioned something along those lines: on how the work on using Linux for supercomputers was the foundation of Linux for phones. It's a point Tannenbaum makes in Modern Operating Systems: what is old, is new, and what is new is soon to be old, as the bottlenecks move, ideas that were abandoned get resurrected.