If you noticed a new patch released via Automatic Update on Friday and can't figure out what it's for, you aren't alone. A quick poll among my usually knowledgeable experts reveals they are mystified as well.
KB 3035583, entitled "Update enables additional capabilities for Windows Update notifications in Windows 8.1 and Windows 7 SP1," is an optional patch. Unless you've opted to automatically install optional patches (a decidedly risky proposition), you'll have to check the box next to the patch in the Optional list, before it will install on your system -- which is all for the best.
Here's the only information I can find about the patch. The KB article says:
This update enables additional capabilities for Windows Update notifications when new updates are available to the user. It applies to a computer that is running Windows 8.1 or Windows 7 Service Pack 1 (SP1).
If you're able to parse those sentences, you're a better sleuth than I. Nary a hint as to what "additional capabilities" are involved. Windows Update notifications are pretty straightforward -- in Windows 7 and Windows 8.1, they pop up as balloons on the lower-right corner of the desktop. I haven't a clue how they could have "additional capabilities."
Conjecture at this point: It's somehow related to the ability to upgrade directly from Windows 7 or 8 to Windows 10. But of course, the official documentation doesn't say anything of the sort.
I'll post more info, if it becomes available.