Android won't be on PCs as it is designed for mobiles in mind. Google had to design 3.0 specifically for tablets, as all other flavours of Android really don't give the tablet justice. Hence why Google has been developing Chrome OS for laptops.
On topic; Vista really isn't anywhere near as bad as a lot of people make it out to be. Sure it has its problems, but that is purely down to the fact that Microsoft were taking too long with Windows 7 and had to ship a new OS.