Right on time, per Microsoft's schedule, the company has allegedly sent the big Windows 8.1 update to "release to manufacturing" status.
That's according to Windows SuperSite's Paul Thurrott, who tweeted that the final build number for Windows 8.1 will be "9600.16384.130821-1623." He eventually sent a few replies to clarify what his otherwise cryptic tweet actually meant.
ZDNet did a bit of digging based on the announcement. Oddly, Microsoft isn't going on record to confirm that Windows 8.1 has officially hit RTM status. However, internal sources have said that Windows 8.1 has indeed hit RTM status, and an official email was allegedly dispatched around Microsoft recently to announce the news.
The move fits Microsoft's promise in early July that the final version of Windows 8.1 was on track for a late August release to desktop and laptop manufacturers. In other words, OEMs.
Microsoft announced in mid-August that it was targeting 18 October as the official launch day for consumers.
Those looking to play around with Microsoft's big tweaks to Windows 8 have had ample opportunity via the company's Windows 8.1 Preview, but it remains to seen – or announced – whether some groups will be able to get their hands on a final build of 8.1 prior to its official public unveiling. We're talking, of course, about TechNet and Microsoft Developer Network (MSDN) subscribers.
Members of these groups have traditionally been able to receive early access to Microsoft's various updates — be they large or small — under the presumption that they'll be able to test said final updates well in advance of their official release. This is important, as it allows those running specialised software (for example) to determine whether they need to skip or embrace certain updates, especially if they have the potential to change key parts of the operating system that might otherwise break certain critical programs or components.
Microsoft representatives from the US haven't said anything about whether it will grant these users early access to Windows 8.1. However, a Microsoft Netherlands rep has gone on record suggesting that the 18 Oct launch date (again, New Zealand time) is the launch date for everyone: consumer, corporate user, and developer alike.
If the company does opt to embrace an early release, and plans to fit the timeline it generally uses for subscriber availability post-RTM announcement, then these members can likely expect to see early access to Windows 8.1 around 7 September — roughly two weeks after the RTM date, and a month and change before everyone else.