You could likely run it, but don't expect exceptional performance results.
Your CPU is more than the highest minimum requirements that I've ever seen in any game, needing more than 4GB ram is a little absurd, it helps having more, but you shouldn't need it, but the GPU is now on the low end of the scale, but you should be able to run it on low settings fine.
Still been meaning to upgrade my desktop's old Radeon 2600 XT (my CPU is a Quad 6600 but that doesn't need to be upgraded for a while still), but I'm not a huge pc gamer myself, Dawn of War (Soulstorm) is normally the only game that I play on it lately & that will run on my El'Cheapo laptop, the original Witcher is $20 in store so I'm considering picking that up.
If you decide to buy a new computer mainly for gaming, don't waste your time on a laptop, desktop all the way baby! But as I said, your current comp SHOULD be able to run just about any game (at least on low).