Acer will soon start shipping the Aspire One D255, a new netbook with Intel's dual-core Atom N550 (1.5GHz).
This is an update to the AOD260 (yes) which adds a new processor configuration and new colors, but drops the chrome elements and the glass splitter like "flake" design. Otherwise it's exactly the same.
The Intel Atom N550 sports two cores, clocked at 1.5 GHz, with 512KB L2 cache each, and supports hyper threading, which results in four threads or virtual cores. It isn't the first dual core Intel Atom, albeit the first intended for netbooks. Both previous models, named 330 and D525, are designed for desktops and so called nettops. This didn't and doesn't stop Asus to build a few netbooks around them. IMO with little success.