Don't get caught up in the amount of RAM the graphics card (VRAM) has because it is limited by the resolution. 512MB of VRAM is fine for 1366x768 resolution. 1GB is fine for up to 1920x1200 resolution. 2GB of VRAM is really not necessary until you hit 2560x1440 resolution.
Of course the higher the resolution, the more powerful the graphics card needs to be to maintain performance. The Radeon HD 7670m is a decent mainstream graphic card for a laptop. In general, it should give you pretty decent performance with medium graphic settings @ 1366x768 resolution for games that are not very demanding. However, for graphically demanding games like Hitman Absolution, Alan Wake, Battlefield 3 and Metro 2033 you need to lower your expectations.