At least one user installed this update without problems
Apologies, this blog post – on a somewhat well-known blog primarily dedicated to physics and philosophy of science – is a test trying to measure how many people will find the blog post identified by a new Microsoft patch that was released tonight, on the September 2015 Patch Tuesday, when the number of Googlable articles about that patch is basically zero.
This patch KB3081455 is a cumulative update for the 64-bit systems running Windows 10. I am downloading it right now and the patch should be ready – perhaps for a reboot – by 8:20 pm, Prague Summer Time. I will update the blog post when everything goes OK, or if I am able to get to the Internet and things are not OK. ;-)
Newer report: I rebooted around 8:20 pm Prague Summer Time, 80 minutes after the update became available, and the reboot process was smooth and straightforward. I don't observe any significant changes of the system. Well, a few minutes after I logged in, the Windows Explorer got silently restarted – the bottom bar with icons etc. disappeared for a while and reappeared.
This update includes improvements to enhance the functionality of Windows 10. Windows 10 updates are cumulative. Therefore, this package contains all previously-released fixes (see KB 3081444). If you have installed previous updates, only the new fixes that are contained in this package will be downloaded and installed to your computer. For a complete listing of the issues that are included in this update, see the associated Microsoft Knowledge Base article. After you install this update, you may have to restart your system. Go to KB 3081455 Microsoft page when the page is ready (it became ready at 8:40 pm Prague Summer Time or so), or a Reddit discussion on the patch.
Windows 10 makes it hard to prevent the system from updating Windows or drivers – Microsoft wants everyone to be on the same frequency defining the state-of-the-art technology immediately (or the whole world to crash on one sunny day in the future) – but if you really need to calm the update procedures down, read KB 3073930, for example.
If you have more information, or warning about some problems, please post them as a comment. It may help others.
Update: yes, after 7:11 pm, I was getting lots of hits, basically 1 hit per second.