That one's been going both ways lately. Apple has been notorious for being late on video cards, but they seem to be getting the latest Intel CPUs and chipsets before anyone else.
I'd expect there to be pretty close to parity on the CPU and support chipsets from the CPU manufacturer. It becomes less of an issue as more stuff gets integrated into those chipsets. If you want to play with the bleeding edge stuff, you're probably out of luck.
As long as they stay focused and committed to the platform, they won't be too far behind. If they decide there's more money to be made in pocket toys you could find yourself falling behind pretty easily. When Jobs retires, the next guy might have different ideas.