Microsoft is changing their upgrading method starting with Windows 8. They are planning to do more annual upgrades that are about the size of service packs instead of releasing a huge new windows os every few years. Its pretty much the same idea as how Apple does their OS upgrades currently. I believe the next upgrade for Windows is Windows Blue but do not quote me on that, I was very tired when I read all this.
Erm... yeah and no? I find a lot of stuff runs slowly/not compatible so it slows down even basic functions for newer PCs, but it is faster to boot up on older PCs. That's about it, I still prefer Windows 7.