My old Gateway laptop with a Geforce 6100 GPU and a dual core 1.6GHz turion TL-50 processor can play COD4 at playable framerates on the first level and a couple others. It really hits the chip with the second level with the rain. Considering the x1200 performs similarly, I could see 20 fps being your best not your average. In more demanding levels framerates will drop below playable. My friend has a similar Acer laptop with an x1200. When we play multiplayer with his laptop, we're limited to the "shipping" level because that is the only one where he gets acceptable framerates.
Your second claim with the 2.7GHz dual core does not mention the GPU? x1200? I doubt the cpu would make any difference with an integrated GPU so weak. And honestly, anything below 30 FPS average is unbearable.
So you've heard our arguments I guess. What quality settings do you intend to play warcraft 3?
Also I should have asked before, are you looking at a laptop, motherboard or OEM computer?