
Originally Posted by
Grizzly
I think it is fair to say that it is overkill now, and overkill forever. The main aim on tech these days is not performance, but power effeciency, with newer generations of hardware requiring less and less power (Look at, say, the power difference between the Q8400 and the Ivy Bridge i5 - the latter is faster but requires less power).
On the other hand, having a 750 watt PSU will mean that you probably will never have to upgrade that thing ever again. And, as a side bonus, a PSU that can perform reliably at 750 watt will most certainly perform extremely reliably at 500 watts, and reliability is all you want when getting more expensive components (PSUs have a nasty tendency of doing splash damage when they go down). It will probably also last quite a bit longer.
Personally, though, I'd rather go for a 600 or 650 watt PSU, and invest the money you save on the other components. A 750 watt PSU is only requiered when you plan to build a computer with the high end i7s or AMD processors, and if you crossfire or SLI two or more graphics card. But if you had the buying power to do that, you wouldn't be here asking if you should upgrade your CPU or GPU first.
There is, unfortunately, no defintive answer I can give you on that point.