We have been expecting a relatively major update to Windows 10 in the October-ish (which at some point the rumors slipped to November-ish) time frame since the OS launched in July. We already know much of what will be in it, based on the preview builds being sent to Windows Insider participants, so the contents are not really a surprise either. It will update a few user interface elements, tweak how System manages memory, and allow clean installs using Windows 7 and 8.1 product keys that qualify for Windows 10 upgrades.
Really, the major news is how the update will be delivered. I was honestly expecting to do the in-place upgrades that each new Insider build forced upon users. This made sense to me. If you have installed Windows 7 recently, you will know that it is a several-hour updating process that involves several reboots and gigabytes of patches. The build metaphor makes sense in a “Windows as a Service” universe, where all PCs are pushed from milestone to milestone with a few incremental patches in between.
Apparently, it will just be pushed down Windows Update in an item named “Windows 10 November 2015”. That's it. Pretty much the same experience as downloading service packs over Windows Update in previous versions. Oddly familiar, especially given the effort they put into the in-place upgrade interface over the last year and a bit.
Maybe we'll see that in future feature-updates?