Yep, I think the A8 (or A7X) could be really close to the performances of entry level CPUs used in MacBook air! An A7 scores 2564 and an i3-3217U 3095. But if you look at the Atom Bay Trail, which scores 2630, you see that Intel did a nice coming back in the mobile segment, at least for tablets.

In the case of a quad cortex A7, like the one in the Moto G, or the MediaTek MT6589 in the bench comparison, we see that the performances are too bad to replace a laptop. With a score of 1258 it is comparable of the best good old netbooks with Intel Atom.