You can use a ton of laptops for gaming, I don't know what they are talking about. Desktops are just more recommended because you can get more power out of them, obviously when your working with more space like that, your going to gave more power options. But yeah, Nvidia or ATI for the most part. ATI drivers suck though fyi.
I got to disagree with you Most laptops have integrated gpu and you cant really play the new games with them.
FYI When you buy sony vaio you are buying brand.
Asus Gameing Notebook (great cooling) GPU:5870 1980x1200
Sony vaio expensive and ripoff