According to
the latest roadmap from Microsoft, it would appear that Windows 8 will arrive sometime in 2012. This would follow a three year product cycle that would keep it in line with Vista and Windows 7 releases. The road map is clear about the targeted date and does not try to hide the fact that the code name is "Windows 8". Little else is known about the OS other than its targeted date of release.
Well, if Windows 8 does not come as a major improvement on Windows 7 (i don't know what that means, as Windows 7 is solid, both in terms of quality and features), it will have a hard time convincing the buyers. 7, besides the features and stability, and everything else, had the advantage of launching on a market splitted between an old OS, although still loved by many/me ;) (Windows XP), and a flawed OS (Vista). Windows 8 will probably find a market dominated by a modern OS with lots of good features and good stability and security.
)