Btw, I tend to agree with you,and think Intel's engineers are just being lazy wrt power. I expect this Nvidia chip to get crushed technically when Intel's engineers gear up and really work on power (like they did when Transmeta's Crusoe came out).
Why is Intel having trouble broadening their horizons? Is it an institutional thing, that the teams not working on the main (and most profitable) CPU product lines just can't get the resources needed to catch up with the competition? Intel always has the latest and greatest fabs, but it seems like the designs they're producing for these new product lines are completely squandering that advantage and then some.
I don't think Intel is being lazy, but Atom is certainly an immature design and the mainstream Intel cores target a much higher level of performance; brainiac cores are fundamentally inefficient because power efficiency decreases as performance increases (in other words, each marginal increase in performance costs more in power than the previous one).
Thumb has benefits, but there are also limitations which is why I wouldn't call it a replacement.
One of the big differences is that you now need a marker instruction for predicated sequences, but obviously the encoding is quite different.
That said i've heard/read that Thumb2 tends to be the optimum size/space trade-off, but that's not because it's somehow more 'cisc'.