First, we'd like to see screens that are of high quality and resolution so people don't end up straining their eyes trying to read the tiny fonts on these little things. Websites may also face a challenge of keeping things scalable for such low resolution browsers in the future, so keeping the resolution high and screens a decent size (we say don't get anything lower than 11-inches) will definitely alleviate all that unnecessary squinting.
Secondly, while making them gaming computers seems a bit ridiculous, we'd suggest having a video card and processor that's strong enough to do a couple of common tasks without slowing down. For example, streaming YouTube video while chatting on AIM should not be an issue for this time in age. The ability to output to a high-definition television would be pushing it, but we'd welcome the addition nonetheless.
Oh, we can only dream right...? Help us dream, readers! What do you want to see in the next killer netbook?