Basically here's the problem:

Apple is a very innovative company but they are stuck with the Motorola PowerPC. Motorola can't afford to keep up with AMD/Intel in the CPU speed wars because the quantity sold is so vastly different.

So now the latest Macs are stuck with CPUs that run at half or less the clock speed of new Pentium IV's.

Steven Den Beste has some articles that touch on this:
Mac's Free Ride (http://denbeste.nu/cd_log_entries/2002/07/MacsFreeRide.shtml)
Mac the Hammer (http://denbeste.nu/cd_log_entries/2002/07/MactheHammer.shtml)

Going to a different CPU (like Intel and AMD) could be very time consuming (years to do). What is to be done?