Alienware overcharges and underperforms - that thing won't manage three monitor gaming very well, and yet it's got stupid wastes for single-monitor gaming.
My strong advice is to return it and buy from Falcon NW if you absolutely can't build one, but listen to this first:
Building your own computer is EASY. It's LEGOs for adults, and there are millions of good youtube videos walking you through how to assemble it. Tom's can help you get what you're looking for at a good price; it'll be close to twice as powerful as that computer, and likely cheaper. (That hardware costs about 1.5k, at most.) As for warranties, well... most parts come with either a 3 year or a 5 year warranty, do you have NOTHING to worry about.
for $2000, you could've gotten a better value out of it running 2x670's in SLI with a 3570K. made a much better sense than an SB-E i7, that brings little performance over an i5 for the price, and a single 680, for 3x1080p monitor setup.
OF COURSE, this rig will run any of those games at Ultra.
There's a catch.
Obviously it's a bad deal you got there. And plus, 2xGTX 670 is going to
stomp the single 680 when triple monitor gaming.
That 2GB VRAM on the reference 680 isn't going to get you anywhere.
And last but not least, the i7-3820 is good but not worth the money.
No one should blame you for going with an OEM; everyone has a first time right (heck, I even went with
Dell and got an XPS 8500 with a piece of crap videocard)? But next time, just go ask for build advice in the forums
and go build your own.