2012 there is going to be more changes in next OS. They're planning for the next OS in 2012 and so i think windows 7 will have shorter lifespan than vista or windows XP. Windows 8 will only require new hardware and it will run on most of the low memory configuration. This is what i have read from the online magazine. I have seen that it was tested on 512 MB RAM and it is performing fine like Windows 7. Also they're releasing separate version for both desktop and tablet in future in order to make the navigation and operations easier.
I don't think windows 7 will be recieved in 2013 like XP. Because XP managed to survive for more than 9 years and counting. In case of windows 7 which was launched in 2009 i guess is yet to cover the whole market. Many new computers are still running on old hardware with windows XP. When windows 8 launches then i guess it is possible
interesting... would be awesome to see Windows 8 running on lower spec hardwares... one of th reasons i stayed away from Windows 7 since it's release was hardware requirements... although my PC now can perform perfectly well with Windows 7, i just don't see the point of upgrading as XP serves the purpose adequately
If Windows 8 is coming out soon... i will probably upgrade to it, but i will see if it will be as slick as XP hehe