I should have known better than to get my hopes up.
From InfoWorld, via Slashdot:
It's back! Microsoft’s Get Windows 10 app, KB 3035583, reappears
The nagware upgrader’s fourteenth version in fourteen months arrives with no fanfare
Once again, Microsoft has unleashed the GWX Kraken, with no explanation and no description. The latest KB 3035583 appears as a “Recommended” optional patch for Windows 7 and 8.1. Those with Automatic Update turned on and “Give me recommended updates the same way I receive important updates” checked -- the default settings -- will see the patch as a checked, optional update, and it will be installed the next time Automatic Update runs. If you previously hid KB 3035583, it’s now unhidden.
I’m sure there are a dozen people on earth who still have Auto Updates turned on, “Recommended updates” checked, and who haven’t yet accepted Microsoft’s kind invitation for a free copy of Windows 10. This one’s for them.
[...]
Microsoft describes the now-notorious method for dismissing the upgrade, hidden in a tiny link on the “Windows 10 is a Recommended Update for this PC” dialog, in its explanatory post KB 3095675. I was quite surprised to find that, as of early Thursday morning, the “Windows 10 upgrade: How-to information on scheduling and notifications” post has not been changed. It’s still at Version 12, dated May 18.
Lesson learned: from now on, I'll just assume that Microsoft are beyond redemption.
If you're wanting to avoid having your system upgrade automatically to Windows 10, check now to see if your system is about to auto-install update KB3035583 -- you should also check your installed updates, to see if KB3035583 has been installed already, and uninstall if it has. Unless you're wanting to switch to Windows 10, of course, in which case you're golden, because Microsoft apparently can't wait to switch your PC over.
(Seriously, Microsoft... 14 versions in 14 months?! That's just desperate.)
I won't be switching, and to guard against this kind of chicanery, I also have GRC|Never10 running on my PC; you might want to check that out, if you're also wanting to be in control of what Microsoft installs on your computer (and when).