Get an X80r if your shopping in the UK 1400 pounds gets you an 8800MGTX, T7700, 4GB, 320GB scorpio, 17" 1920x1200, 8.5lb, 44mm thick , get a Gateway P-6831FX if your shopping in the US equivalent to 690 pounds gets you an 8800MGTS, T5500, 3GB, 250GB scorpio, 17" 1440x900, 8lbs, 3.5mm thick (upgrade the CPU to a T7500 and HDD to a 320GB scorpio for ~200 pounds).
None of that 2k pounds rubbish said earlier and a system to rival some of the best non-sli, dual core systems you can buy today. My system (the P-6831FX with the upgrades suggested) scores over 9K in 3dMark'06, and at 1440x900 (since its native I get no scaling artifacts higher res's get, if they run at the same settings)I can run Crysis at high no AA, 4x AF and its very playable (~30fps average) except in extreme firefights (drops to 9fps) (as with even the greatest tri-SLI systems today).
Also tbh unless your particularly weak, or want a small laptop theres no reason to get the DELL, for what it is, its a complete rip off compared to what I suggested above. With the Gateway I get 3.5hrs on power saver mode with wifi on and browsing, around 1.5hrs when I play games high performance mode. With the X80r people are seeing around 1hr play time.