Many people are focusing on the release of Apple hardware using the intel x86 processor, but that's not the real news. The real news is that Apple has released x86 compatible software. It won't be long until people figure out how to boot Windows on the Apple machine and bypass the EFI hardware layer. It'll perhaps take an extra month for people to figure out how to get OSX running on non-apple hardware. Both of these will be a very good thing for Apple.
Why? Developers, Developers, Developers. Having a single architecture means that curious developers have nothing to loose by trying out the OS, and more developers playing and exploring a new OS ultimately means more applications.
Let's assume for a minute that Apple would like to take a larger slice of the desktop pie. Ok, now how do you do it? They've built a more advanced operating system, they have more innovative hardware, they have great marketing. They have a better ship schedule and a better track record in the security area. Why doesn't Apple have 90% of the desktop market?
Ultimately it comes down to choice, people like to make 'correct' choices. On one side you had Sony, Dell, Toshiba, HP, Microsoft, IBM all telling you that X86 is the right choice and on the other side you used to have Apple asking you to make a different choice.
The stars are now aligned, the stage is set, the playing field is level.
Let the battle of the desktop wars begin.