Windows Blue is a brand new feature pack for Windows 8 and all Microsoft-related devices. It will come out in Summer 2013 and it will be known as Windows 6.3 for Windows Updates. Its build number will be 6.3.9304.
Thanks for the links. And I think this is good news: "According to that posting, the Core Experience team in Windows Sustained Engineering (WinSE) is involved in making improvements to the start screen." The start screen is not so good today. I hope they will improve it, a lot.
As long as there isn't any confirmation from Microsoft, all of that just are: RUMOURS! Microsoft explained in some pst reports that Windows Blue will be actual an huge Upgrade to Windows 8 but a new OS, a Feature Pack or whatsoever. Next Generation of Windows OS will be Windows 9 as also reported several times already. The name an Upgrade as Feature Pack is just misleading.
This one is even worse than the previous winblue thread. If it's true, Obama would resign from his office and let NTMarta take up the post.