AMD recently added
two new dual core CPUs to their lineups, the 5400+ and the 5600+. Both CPUs are operating at 2.8GHz, with the 5600+ variant coming with 2MB of L2 cache and the 5400+ coming with 1MB. These are based on the existing processes and technology that other cores are using, so performance and power estimates aren't going to be all that much different from other AMD offerings. We'll still have to wait for 65nm versions and core revisions from AMD, which they definitely need to compete with Core.
They are both AM2 processors. The 3.0GHz X2, the 6000+, is still not yet available and the launch date has not been announced.