Microsoft has reportedly completed development on the Windows 8.1 update and signed it off as (released to manufacturing) RTM. This indicates that the final version of Windows 8.1 is headed to manufacturers, so that it can be included in devices in time for the upcoming holiday seasons later this year.The final version of Windows 8.1 is expected to be made available to users through the Windows Store on October 17, and we can expect Microsoft will continue fine tuning the platform before it reaches our computers.
Between now and then Microsoft will release a series of “quick fix engineering” (QFE) updates to the manufacturers while they prepare their new lineup of devices.
This is a process that Microsoft has used in the past, most recently in the development of Windows 8. With users having pointed out things they would have liked to see improved in Windows 8, Microsoft has been able to continue fixing issues with the platform and hope to make is at reliable as Windows 7.
Meanwhile Microsoft is also working on Windows RT 8.1 and Windows Phone 8.1 updates. Windows RT 8.1 will likely debut on the second generation Surface tablet alongside Nokia's first entry into the Microsoft tablet market. Windows Phone 8 will first see the GDR 3 update later this year, which promises to bring 1080p support. Windows Phone 8.1 is expected sometime in the first half of 2014 and should unify Windows across Phones, computers, tablets and the Xbox.
We can expect a public announcement from Microsoft regarding Windows 8.1 sometime this week.
source - Windows IT Pro