AMD's as of yet unreleased Puma platform has shown promise on paper, and recent rumors make it more so with details of four new processors that will be made for the platform. In particular, the Griffin code CPUs will have a small clock speed range from 2GHz to 2.4GHz, from 512kb to 1MB of cache and a thermal profile on par with most mobile CPUs.
They claim that the CPUs are more efficient than the existing Turion CPUs, though the real competition should not be between their own models but between them and Intel. While they are doing well in the TDP department with these CPUs ranging from 31W to 35W, Intel has promised mobile chips with TDPs as low as 5W in the coming years.
The Puma platform, even though unreleased, already has a pseudo-successor planned. AMD is certainly busy, which hopefully means they are doing well.