PowerMac G4

I don't know the answer to your specific question, but I think the answer shouldn't matter. For Final Cut Pro, you want the best processor you can afford. You have a certain budget and you'll buy the best Mac available for that price at the time of your purchase. Apple tends to keep roughly the same price points over time, so each time the Mac lineup changes, you just get more for the same price at each price point. Waiting until January will help you in two ways: you'll get the student discount and whatever you buy then is bound to be a little faster for the same money than what you'd buy today. It could be one of the current G4s with a lowered price. It could be one of the current G5s with a lowered price. And no doubt there will be newer, faster G5s with the same or higher prices. The disadvantage of waiting until January isn't that a particular model will be removed, it's simply that you won't have a Mac until then.