It's a little embarrassing the coolest processors we have today are more or less binary compatible with processors of the 70's and 80's and that the operating systems they run follow fashion that was conceived at that time.
I have said it before: where are massively-parallel, hardware-assisted garbage-collecting connectionist machines of today? "Nowhere", we say, mostly because they can't run Windows.
What happened to Alan Kay's "if you are serious about software you should build your own hardware" idea?
And just imagine how happy would Intel and AMD's engineers if they could make all the silicon around the execution units of their processors do useful stuff instead of emulating past 8086's 80286's, 80386's, 80486's, and Pentium I, Pro, II, III, 4, MMX, SSE instructions (and quirks) for binary compatibility's sake.
Contrast aggressive register optimization for function calling on most RISC boxes with SPARC's moving register window or the hoops you have to jump through on register-starved instruction sets like x86s.