Well... it's official...

Apple is switching to Intel processors.

I haven't checked yet, but I'm betting hell is pretty cold right now.

The world has been turned upside down.

Wow. I mean... wow.

This also puts me in a very interesting place... I've sworn never to buy another Intel chip, in guise as an Apple product or not.

Apple, I don't mind saying this: I think this is the worst decision you have EVER made. I'm sorry Steve, but this is just idiotic, I mean plain old idiotic.
Do you not realize that the x86 platform is one of the hottest running out there? And the amount of power it sucks... wow.

How are you going to maintain the blazing speeds we've seen on your current Powerbooks, etc. AND the small form factor?
My Powerbook G4, 1.25GHZ PowerPC is just as fast or FASTER than my Vaio 3.0GHZ Pentium 4, but it's half the size. Do you know why it's half the size? Because you have to put a turbojet inside a P4 machine to keep it cool.
Ignorant fools.

Again, this is the probably the worst thing you guys have ever done, I'm astounded, I really am.
Steve Jobs, I have a bad feeling you're going to live to regret this.

EDIT: Before I get too much verbal laceration from somebody.. I've just noted that according to at least one source Intel chips run cooler than PPC chips... eh? I'll have to look this up... I'll get back to you all

EDIT: OK, so now I have Apple talking out of both sides of its mouth... here: http://www.apple.com/powermac/performance/ We have Apple touting it's G5 processors, quote: "The PowerPC G5 out-shoots the Pentium 4 in a battery of tests. But it’s in the rough-and-tumble of real-world performance that the G5 really shines — shredding the PC’s reputation in the process."
Might wanna revise that soon, Steve... dissing your new product with an existing product? Tsk tsk.

Their favorite talking point is that "Intel runs way cooler"... I don't know where they got that... every Intel I've ever used ran hotter than any other chip I've used.. PPCs, AMDs... they're just better.
WHY??? WHY??? I'm sure Advanced Micro Devices would have dealt with Apple, why did you do this Jobs, WHY?
I think you've lost a customer, congratulations.

EDIT: Now.. for answers a couple of the nagging questions...
Q: Will I be able to install Mac OS X on my garden-variety Dell, HP, etc?
A: No, according to everything I've seen so far it will only run on specially modified Pentium chips. I took this cue from the fact that the Intel development kit($999) ships with OS X 10.4.1 AND a Pentium 4 3.6GHZ CPU.. why ship a non-required CPU? There's something special about it.

Q: Ok... so... now that we have Intels in Apple boxes, will I be able to install Windows on my Apple computer(s)?
A: This will more than likely NOT be supported out of the box, though obviously there's going to be a pretty serious effort to get both this and the above item(OS X on any P4) working.

Qs/As taken from stuff I've seen while browsing around like crazy this afternoon... hopefully this info is pretty decent guesswork. :-) I'll edit with any updates.