@Nitro: Judging by the OP, yes, it is out of the question.
IMOP the Alienware Aurora ALX is overpriced, but that is true of many pre-built i7 rigs. I'm bored, and at work, so I'll go through the customizer with you.
Processor: the i7 920 has proven itself the beast of the line-up; cheap, overclockable, durable. So much so that Dell offers an OC option from 2.66 to 3.2ghz for
ONLY a $200 upcharge. Highway robbery for an overclock job, but your only OC option if you're buying from Dell.
Win 7
Home Premium 64 bit; if you don't know the difference already, you won't miss the addons that make Ultimate ultimate.
Video cards: While dual gpu utilization has improved recently, it hasn't won me over. That said, Dell is only offering 1 option with a single processor and its ATI... (I'm not an ATI fan) nor am I a fan of putting two $100 GTS250's into a $3000 rig. I use an old 512mb card and will be upgrading shortly, 1gb seems like enough, but if you can afford the better card, go for it.
Ram: 6gb would be sufficient, 12gb would be better, 24gb just costs too damn much. You will never notice the difference between 1066 and 1333 in RL usage (you would in synthetic benchmarking)
Hard Drives: Dell is offering Raid 0, which is essentially two hard drives, each of whom get half the data, so they only have to do half as much work, theoretically making it twice as fast as a sin
gle drive. (further reading http://en.wikipedia.org/wiki/RAID) I would venture a guess that 600GB RAID 0 (2x 300GB SATA-II, 10k RPM, 16MB Cache HDDs) are dual VelociRaptors (two thumbs up)
Additional Hard Drives: They offer Raid1 arrays, which again, are overpriced, but offer you good storage that is protected from loss due to HDD failure.