Microsoft yesterday said it will officially launch Windows 8 in late October when it starts selling upgrades and its hardware partners begin selling PCs, tablets and hybrid devices powered by the new operating system.

Windows 8 is also on track to reach “release to manufacturing,” or RTM, the first week of August, said Tami Reller, Microsoft’s CFO as well as the head marketing executive for Windows. Earlier reports had suggested Microsoft was eyeing an October launch for its next-generation operating system, but Monday marks the first official confirmation from the company that Windows 8 will in fact debut in October. No specific date in the month has been set.

The October ship date, or as Microsoft calls it, “general availability” (GA), has been long expected by analysts. Using prior development cycle timelines, primarily that for Windows 7, Computerworld had pegged Oct. 25 as the most-likely launch date for Windows 8.

It’s likely that subscribers to Microsoft’s for-a-fee developer services, including MSDN (Microsoft Developer Network) and TechNet, will also have access to Windows 8’s RTM code around that same time.

Windows 8’s GA date is important because that’s when OEMs will roll out new PCs and other devices to retail.

According to a follow-up blog post yesterday by Microsoft spokesman Brandon LeBlanc and Reller, the hardware will include desktops, laptops, tablets and so-called “convertibles” — machines that combine elements of notebooks and tablets — powered by Windows 8, and tablets running Windows RT, the offshoot designed for devices with ARM processors.

October could prove to be a particularly busy month for the technology industry, as multiple reports have suggested Apple plans to launch its next iPhone that same month, one year after the debut of the iPhone 4S. Apple is also expected to introduce a new, smaller iPad before the end of the year that is rumored to become available ahead of the holiday shopping season.