The problem with huge laptops like these is as follows:
I bought my Sager because I run a LAN party, and go to LANs whenever there's one in the area on a weekend. Lugging all my desktop crap was getting rather old after a while, so I figured I'd buy a desktop replacement gaming laptop. About $4000 later I've got a seemingly awesome little mobile computer that could play any game I throw at it at 1024x768 at max detail settings (anti-stropic, anti-aliasing, etc).
The problem lies in the fact that it's neither really an exceptionable desktop, or an exceptionable laptop, it lies somewhere in between, and is completely un-upgradable. With my old PC desktop, I'd buy the newest graphics cards when they came out, new motherboards, processors... Essentially if you can budget a few hundred bucks a month towards a PC you'll always have the top of the line stuff.
I can't do this with my laptop... 6 months later I'm left thinking "Well, I've got the 9600, wish I had a 9700... ahh well." When in a desktop, I'd have the Radeon 9800 XT in my desktop the day the cards starting shipping.
So I would have to give the new Dell laptop a thumbs down because of the fact that it may be really cool now, but in a year, you'll just have a laptop that's 4 inches thick that isn't cool anymore, and there will be nothing you can do about it. I'm in the process of selling my laptop and getting a
small form factor PC. This shoe-box sized PC will easily fit in one of those rubbermid tote boxes with an LCD, keyboard, and everything else I need... all the while being completely upgradable.