According to Wzor, Windows 9 will reach Beta in May of this year. This will be the only Beta version of the operating system. A Release Candidate build of Windows 9 will then arrive sometime between late August and September of this year. Sign-off for the final build of Windows 9 will take place sometime between the end of October to the middle of November. Wzor is sticking to his claim that Windows 9 will hit RTM between October 21st and October 25th.
However, the well-connected Mary Jo Foley over at ZDnet recently said she heard from her sources that Windows 9 Threshold RTM will not hit RTM in October 2014, as rumored by Wzor. According to Mary Jo Foley, "By the way, for what it's worth, I'm hearing from my sources that WZor's claims this week that Threshold will be released to manufacturing in October 2014 are inaccurate. Maybe he's hearing about something like another Windows 8.1 Update."
Microsoft is expected to introduce a plethora of new features including floating modern apps as well as some sort of "mini" Start Menu, but it seems they'll not be a part of the Windows 8.1 Update 1, according to Foley. It could, however, make an appearance next year with Windows 9.