The problem with the netbooks, and the new ultra low voltage laptops is that the video RAM is typically only 64MB. The newer ULV laptops with the better Atom processors weigh about the same as the netbooks but they have 13" screens and more normal keyboards...however they are much more expensive ($600+). The nice thing is that some of them have up to 4GB RAM, and can run business applications really well, but one of the big savings on power consumption and thermal control is stripped down video processing, so I don't think any of the offerings are going to be suitable for most games. If you don't need ultra portability, you might look at a regular laptop so you have more video choices.
-Skylark