It will.
Apple has said they bought P.A. Semi to create custom chips for their portable devices:
http://blogs.wsj.com/biztech/2008/04/24/jobs-still-hearts-in...
A whole load of stuff is being released Intel-only now. The newest PowerPC machines are now two years old, so if you're releasing something that needs a this-generation machine to run reasonably, why bother?
This proportion is only going to grow over time. And it will probably be riddled with endian bugs, alignment assumptions, and x86-only toolchains. Going back to PowerPC would be at least as traumatic as the initial switch.