The Athlon 2650e will be a 1.6GHz part with 512KB of L2 cache, and the Athlon X2 3250e will be a 1.5GHz part with 1MB of L2 cache. They will have TDPs of 15W and 22W, respectively, quite a bit more than the Atom which uses anywhere from a third to a fourth of that much power. The platform as a whole won't be more power-hungry than Intel's offerings, as the CPU + Chipset together will still have a TDP of 27W, the same as a 945G Atom-based offering. The CPUs will be sold at a fairly low price point, as low as $40, aimed at the “Ultra-Value Clients.”
The Atom is doing well right now, though there is clearly room for improvement in the low-power market. Via’s Nano has a lot of changes planned, some vendors (like Asus) are preferring the Celeron over the Atom and the performance of the CPU still leaves a lot to be desired. If AMD's low-cost, low-power CPUs can give the Atom a run for its money in both price and performance, they have a good shot at stealing away some of its market.