As thestateimin said, the purpose of the Sentia is NOT gaming. It's a 4lb lappy designed to be a good all around powerful system. If you need a gaming laptop, go with the 12lb area 51m with the big screen and desktop processor/vid card.
As far as finding the same stuff cheaper either from dell or hp or whatever, if you check carefully, you'll see that's not exactly true. AFAIK, all of the hd's on dell and hp lappys are 4200 rpm. The sentia can have anywhere fom a 4200 to 10000 rpm drive (selectable by the customer). Also, I'm not sure, but I believe that the l2 cache of the alien processors is bigger (higher) than the dell and hp (but like i said I'm not sure about that). And, the sentia comes with a free dvd burner (at least mine did).
Also, there is the build quality factor. I have an hp ze notebook which is just over a year old. Already, I have had to send it back for the keyboard (some keys stopped working), and the pc card port doesn't work anymore now. Also, ethernet cables just slide right out of the ethernet port. Basically, you get what you pay for.
I don't mean to be a basher, I just think that a computer (like a car) is a really important purchase, and you shouldn't necessarily go with the cheapest. After all you will have it for at least a year or two. It's like the difference between a Kia and a Toyota. You can get a Kia a lot cheaper that a similar Toyota model, but would you rather save a few bucks, or spend a few more for the quality and reliability that Toyota is known for?