You can build a decent gaming machine for half that money. With a few notable exceptions, there are very few games on the market at the minute that will exceed the capabilities of a current midrange graphics card. This is symptomatic of games consoles stagnating the industry - although it's likely to change be the end of this year.
I wouldn't bother with the I7 processor, unless you're using it for rendering, etc. Also, (and i may be wrong on this) Windows 7 professional is the only OS that can utilise any more than 8gb RAM.
My system is an I5 2500K processor, 560ti graphics, 8gb ram and 64gb SSD. It's been that way since this time last year, and it's marvelous and cost me about £800 to build. It's currently running at a stock 3.6ghz, as i've never needed to OC it (in fact, i've undervolted it). If i need more performance in the future, there's scope to clock it to 4.6 or more.
In summary, personally i wouldn't spend that much on a machine.