a couple of the latest lappys do have the facility ... but generally speaking .. the only upgrade that is available would be to swap the LCD for one of the new shiny black jobbys . and that's not going to improve performance.
If you have caught the gaming bug - think about a desktop...
heavier on your knees but � for � more powerful and over time much more scope for upgrades
Other manufacturers have similar projects in (probably) less advanced stages of development, so I guess that there will be the usual drop in price once they are more common.