Simply Acer are now selling the Acer 8935G fitted with a Intel Q9000 quad-core processor for just under £700. Not that long ago, this would have set you back £1400!
This gets you an 18.4" 1920x 1080 Full HD screen, a Bluray drive, 4GB of RAM, a 500GB HDD and a still very respectable ATI 4670 dedicated graphics card.
I would buy this myself but whilst the Q9000 is massively powerful for some things, it's not that great for games which are not optimised for multi-core processors. Shame. However if you are running CAD applications, this could well be the machine for you.