Windows 8 has been released to manufacturing (RTM), the final milestone prior to Microsoft releasing the code to its OEM partners. RTM marks the last point of product development and testing, after which Windows 8 is passed over to OEMs with no further changes until any future service packs or patches; Windows 8 itself is expected to go on sale October 26.
At that point, both new systems running the OS will be available, as well as stand-alone upgrades for $39.99 for existing PCs. Meanwhile, eligible Windows 7 PCs bought from today will get a free upgrade to Windows 8 Pro for $14.99 through the Windows Upgrade Offer.
For developers, there are a few more milestones along the way. As of August 15, developers will be able to access the final version of Windows 8 via their MSDN subscriptions. That date will also see IT professionals in enterprise able to access Windows 8 through their TechNet subscriptions.
The following day, those with existing Microsoft Software Assurance subscriptions will get early access to Windows 8 Enterprise, allowing them to test deployments in the workplace. As of September 1 there will be volume license customer availability through Microsoft Volume License Resellers.