With brand new equipment (64bit desktop CPU), you're going to pay a lot more in the beginning than you would 6 months from now, when there are many more flavors of it available.
It is what is known as bleeding edge technology. You can be that person with the latest and greatest thing, but a few months down the road, you could easily have something equal to it, or a little bit faster for less than what you paid for yours.
I would not buy bleeding edge hardware- unless it is radically different than what I have now, and if I really can't live without it.
Personally, I will only upgrade things like CPU when- it is noticably slow in applications/games, if it is over 3 years old, or if a new CPU is out that is essentially twice as fast as what I have now AND if it is under $100.
New stuff is cool, don't get me wrong- but I no longer get satisfaction in upgrading every few months just to keep telling myself that I have the fastest computer around.
-ben