1.500W is not that crazy
Well, just to illustrate how a 1.500W psu is not insane:
First - The PSU will not use 1.500W all the time. It will only provide what your system is using. If your system is requiring 500W, the psu will pull 500W from your house outlet (if the efficiency is 100% - otherwise, the psu will pull more).
Second - Playing a game or doing 3DMark is not even closed to a High-End System BURN IN.
Third - Just to illustrate: the system below works fine with a Corsair 1.000W psu (PS: Works fine = Play games like Crysis).
But, if you put two little programs to run together, like Prime95 and Furmark... my friend, you will see some real impressive numbers on a Power Analyzer connected to your outlet. These two programs are great to put the CPU and GPU on a very high load (which will drive the power requirement to the roof). With the Corsair 1.000W, you cannot even start both programs. The next? A 1.250W is the best choice for a system like these (if you are really putting it to work hard). And you barely will have that much Watts on hold for a future TEC.
Asus Rampage II Extreme, Core i7 920 D0 @ 3,6GHz (no changes in voltage... all AUTO), 6GB Corsair 1.800MHz, 2x GTX 295 from PNY, Velociraptor 150GB, four green neons, 6 Noctua fans, one Swiftech MCP 650 pump and a blu-ray.
Fourth - It´s better to have the choice of a 1.500W and not need it, than not having and have the need for one.
Fifth - Hey... there are some servers using high quality desktop psu... why not a 1.500W (even though it´s not redundant)? A 1.500W can also be a great duo for the Asus P6T7 WS SuperComputer and the trio or quad green company (NVIDIA Quadro + Tesla)...
Sixth - bragging rights, baby...