Apple is now at a point where they can afford to jump on the Intel bandwagon. And it's not because of the chip or the speed. It's because they are positioned to fend off two possible problems with the move. 1) a drying up of hardware sales during the conversion. 2) MIcrosoft strong-arming Intel to make decisions that are not beneficial or even harmful to Apple.
Does the change really matter? The Apple OS is clearly superior to the Microsoft OS. And one doesn't have to be a pundit to see that. The OS will run just as well on Intel as it does on the IBM series.
The consumer on the other hand (relatively uneducated) will hear "Intel" and believe that now, Apple is playing in Microsoft's world so there's more reason to switch. The truth is that the applications will be little changed. Sure, any application that is trying to do cross microchip emulation will be great. This consists primarily of Virtual PC.
The most important issue will be lost. Apple has an OS that can run on any microchip. They can change that out almost as easily as they can swap out the video card. The real question becomes.... once this change occurs... what happens if Microsoft decides they can move to IBM's PPC series?