Latest a6 chip has benchgeek score of 1757. Macbook Air of 2010 had 2025, new i5 macbook air has 5770.
In Macbooks Apple will have a lot more battery to rely on, so higher clock speed. Can also have bigger sized chips.
It will be a whole different class of chips though.
It is interesting to note that Apple has been spending a lot more on R&D than Intel even on these things