DailyTech has a good summary of it. The most interesting things to me are the fact that it’s designed from the ground up to be quad-core, unlike Intel’s offering, which takes two dual cores and slaps them together (to explain it crudely). It’s thus easier for each core to act independently as the need arises, or work together. Plus, each core is able to adjust clock speed dynamically, which will be especially good for mobile users (and whoever likes quiet CPU fans).
Longevity will probably be good, as the architecture was designed with future memory technologies in mind (i.e. DDR3). Looks like there’s also heavy focus on improving branch prediction and prefetching logic, which is always nice, since it makes the CPU more efficient.
Finally, DailyTech notes that the power planes are split between the processor and memory controller, so that they can operate at independent speeds and voltages. Should make for some interesting overclocking, if the need ever arises. Now we wait for real benchmarks.