I'm not buying an i7 dual core. That's just dumb. I mean, the new phones are coming out with quad cores, wth MS?
You CANNOT compare a quad-core mobile CPU to an i7.
I know synthetic benchmarks are not a be all and end all, but look at these numbers for a quad-core android and the i7 coming in the SP3:
Source - geekbench.com
More cores doesn't always mean 'better'.
But as I said, you can't compare the two, they are designed for completely different kinds of devices, with different power levels needed, different power available to them etc.
The scores above give some indication of raw power, but how that translates into device usability will be wildly different from device to device.
As another, far better example, compare the Surface RT performance (on a quad-core processor) to the SP1 or SP2 with their dual core ones, the difference is phenomenal.