These processors are Intel's answer to the speed race with AMD, as they should be 20% faster at the same frequency than the Athlon 64 X2.
This gain will be in large part because of the reduction of the pipeline to 14 stages (which is much shorter than the P4), while also benefiting from a prediction algorithm which was planned for the longer pipelines. The 4 MB of cache will also add to the performance gain.
The site also provides the mobile processor roadmap from Intel:
