well, enough trash talking, and back on topic please
Of all the laptops you could buy, yes the 9100/XPS is the only one that could qualify as a Hardcore Gamer's rig (sorry AW peeps)
Simply put, only the 9100/XPS with a mr9800 would qualify for newer games. For older games like CounterStirke, UT2k3, Q3, etc., then the rest of the mr9700 crowd can come to the table.
I'm not a "hardcore" gamer, but I am an avid gamer, and do get together 6-8 times a year for lan parties, which are mostly CS at this point. I've toted the 19" monitor and LanBoy aluminum case most recently, I've toted older steel cases, speakers, etc. Considering a lan party usually involves headphones, the whole issue of external sound cards is pointless, unless you really think you need the small extra cpu cycles.
At my last party, 2 weeks ago, I brought my 9100, the bag I carry it in, the power brick, and my mouse. For getting ready, I pulled out the brick and plugged it in, dropped the 9100 onto the table and plugged in my usb mouse, hit the power button, 1 minute later ready to game. Total setup time? maybe 3 minutes.
Tear down time? Started shutdown in windows, unplugged mouse and wrapped up cord, unplugged brick and wrapped cord, inserted 9100 into bag, zipped up and left
total time? maybe 4 minutes.
When I've brought my LanBoy and 19" monitor to the same parties, we're talking a trip with the LanBoy and a bag with my keyboard, mouse, powerstrip, extra lan cables, power cords, etc., then another trip just to carry the monitor. Get done, disconnect all that, put the keyboard and mice and cables etc back into the gym bag, carry the bag and case back to the car, go back and haul the monitor, all the time being very careful not to loose balance and drop the monitor. There's a lot more work involved for sure.
The 9100/XPS with a 2.8-3.4 CPU and the mr9800 will outperform roughly anything short of a P4/Athlon 3.0 GHz and either an X800 or GeForce 6800 series card. Most gamers don't have those cards, and the 9800 series are still plenty powerful for even todays games. D3 is a little hard on the 9100 sure, but the 9800 will rock at 800x600 which would be fine for a lan party. And HL2 looks to be even better as it's much more tweaked for ATI cards and I dare say once it's out many many more people will play HL2 and it's multiplayer versions than D3.
As others have said, with a few tweaks, there's no reason not to expect performance good enough to be acceptable for lan parties, while also being convient and easy to take anywhere.
You just have to decide if you do want to give up being able to have the absolute cutting edge all the time. If you aren't looking for buy for 6 months, that might even suite you better and by then these systems should be updated with pci-e graphics cards and some may even have nvidias mxm slots by then, which will make video upgrades for lappys as easy as desktops if not easier. and ati is working on something similar.