The hard science behind your processor may not be interesting to you now, but if Intel were to say “Sorry, it’s physically impossible to go any faster,” you’d get real interested real fast. Or not. At any rate, it shouldn’t be a problem yet, as even the major quantum-physical barrier posed by the move (still far distant) from 22nm to 16nm appears to be surmountable, according to research by some guys who probably know what they’re talking about.
And in the meantime, the stage is set for Intel to deliver their next “tick” and “tock” in the form of a shrinkage (giggle) of the Nehalem architecture to a 32nm process late next year, then a move to the Sandy Bridge architecture some time in 2010. After that it’s anybody’s guess, but it’s been like clockwork so far.