One of the benefits Asus may be able to play up is the fact that Android has been built for mobile, low-power hardware. Given the profile of the current Asus netbooks, I'm expecting that we'll actually see the same hardware being used. If not that, then Asus could use an even more slimmed-down unit specifically for the Android OS.
While system responsiveness and functionality could be key for adoption, Android is nonetheless poised to face the same adoption issues as Linux considering a majority of people still prefer Windows on netbooks. With an estimated release before the end of the year, it's also expected that Microsoft will have delivered a supposedly netbook-friendly Windows 7 OS by then.