Right now, AMD would be on top of the world. Their Radeon series of GPUs are phenomenally successful with their next-gen 7000-series just around the corner, their APU is rolling out right now, and they're already powering consoles; the Wii and Xbox 360. Rumor has it that they might end up getting jiggy with all three console makers come next-gen. The Wii-U is set to be AMD-based and now its looking like the Microsoft and Sony console will be powered by AMD solutions.
Both Microsoft and Sony have of course not verified this news, but HardOCP have a reliable tipster roaming the halls of E3 last week. Based on their information, they say that AMD's future console dominance is already a "done deal." Of course, NVIDIA will be... green... with envy but keep in mind they are powering a slew of Tegra 2-based Tablets and Smartphones. AMD are also set to have an opportunity to win contracts for microprocessors for the next PlayStation.
Right now, all three consoles are sporting Power-based IBM processors, even the PlayStation 3's Cell chip has a PowerPC component sharing die space with SPE co-processors.
Further Reading: Read and find more CPU, APU & Chipsets news at our CPU, APU & Chipsets news index page.