Microsoft confirmed this morning that Windows 8.1 has been released to manufacturing ahead of its October 18 retail launch.

Microsoft also confirmed rumors that the new operating system would not be made available early to any customers. Traditionally, the company has made its new operating systems available to MSDN and TechNet subscribers, as well as volume license customers.

This allowed developers to test and update their applications ahead of release day to ensure that there were no day one upsets and similarly allowed IT departments to try out the new software.

For reasons that aren't at all apparent, Microsoft has decided that both of these groups can wait. Just as is the case for people upgrading from Windows 8 to 8.1, the software will become downloadable globally as soon as it's October 18 in New Zealand; this will be 4am PT on October 17.

With a raft of new APIs and new capabilities for Metro-style Windows Store apps, the usual early access would seem important. The strong implication is that come launch day in October, there won't be any software that actually takes advantage of Windows 8.1's new software capabilities, because developers won't have had a chance to develop or test it.