AMD pretty much missed the netbook revolution, doesn’t play a role in smartphones, and they’re not playing much of a role in the tablet frenzy either.
AMD opted not to play in the netbook arena. AMD has finite resources, when compared to Intel, and they have to pick and choose their battles. At the time, they were hemorrhaging money, integrating ATI, and had a server focused core which was behind the performance of Intel equipment, so it wasn’t pressing AMD release an Atom competitor.
The plan was to let the market develop, and then release a chip which was competitive. Even now, netbook, smartphones, and tablets aren’t where the money is. AMD needs to play in the arena, but it’s not going to be a giant profit center for them. This is evident in the Bobcat chip. The Bobcat chips will be able to be used as a desktop/laptop chip and as a netbook/nettop/tablet chip.
x86 chips are still pretty far away from being used in smartphones. They are too big and too hot right now. In a few years they maybe, but not at the moment.