ATOM spend less energy.

But with AMD you can make a laptop with strong performance, low price, and good batery. Not so good as Atom, but AMD platform is better in other ways.
In the end both are diferent and both have their strenghs.

The chips will be OEM-only, and reports suggest that they'll reach the market as soon as December in systems from ASUS, Acer and Shuttle.
We can only hope that more builders bring this toy from AMD.