Aren't Intel taking a backward step? ARM is RISC, x86 is CISC. By putting a CISC core into these processors, surely their efficiency, as Loris said, won't be as good as the RISC cores that ARM processors have.
It seems like Intel are trying to 'improve' their processors by overloading them with features and instructions, much like they did with the x86... anyone seen this before?
We all know how power hungry the Pentium 4 is - which is at the peak of the x86 'let's stuff it full of fancy instructions which will never get used'.