For the same price as that $450 lenovo t500 you can get a Dell Vostro 3550 15" Core i3 Sandy Bridge Laptop
Core i3-2310M 2.10 GHz CPU, 2GB RAM, 250GB 7200rpm HDD, DVD burner 15.6" 1366x768 LCD with Intel HD 3000 graphics.
Includes two USB 3.0 ports, HDMI, eSATA, 8-in-1 Card Reader, ExpressCard/34 slot, LED-backlit anti-glare matte LCD, WiFi, Bluetooth 2.1, HD Webcam, Windows 7 OS.
This will run SC2 on low settings. You'd need a dedicated graphics card to reach medium graphics.