An Asus Transformer with a keyboard can last about 15h, because it has a battery in both the tablet and the keyboard, while still remaining reasonably lightweig

An Asus Transformer with a keyboard can last about 15h, because it has a battery in both the tablet and the keyboard, while still remaining reasonably lightweight and thin. If Apple keeps the same size of the Macbook Air you'll probably see ~100% improvement in battery life compared to the current Macbook Air. If they decide to make it even thinner and lighter, than it won't gain that much in battery life, but I'm sure it will still be a significant improvement (definitely more battery life than an iPad).