[superstructor]

While you are correct that simply adding a core would not result in a 2x speedup you missed the fact that there are other significant differences between the A5 SoC compared to the A4.

* DDR2 vs DDR1 memory (1066 vs 800Mhz)

* possibly dual-channel i.e. 2 64-bit buses instead of one but this is hard to get solid info on atm.

Even so the speed up probably wouldn't be exactly 2x, but it would be close in some applications and make his claims a lot more reasonable simplification for the target market.