What exactly does KB2952664 do?

I think so far that's a couple of replies that seem to suggest that with GWX10 control panel I don't have to be so diligent.  Just install GWX10 first, maybe even use it in monitor mode, then immediately run it after installing the bundle.

Unfortunately I have to do something ASAP, as this weekend I'll be getting the computer that is years behind.  I will manually make the registry change that should prevent GWX10 (NOT the control panel) from running, and if the support is there, the group policy too.  Unfortunately while I think those may prevent the actual upgrade (or downloading same), I'm not sure if the control also removes the nagware.  I've been clean so far, but with hundreds of things to install in multiple iterations, OR the rollup, I'm sure I'll be installing all of them.

Barry,

I do not think that the newly announced "SP2" rollup for Windows 7 will include every update/patch/fix that Microsoft has released since SP1.

I think it is just a rollup of the monthly updates since SP1.

If you have purposely hidden some of the monthly updates (because they were Windows 10 nagware, because they resulted in sending telemetry to Microsoft,  because they were known to cause problems, etc) and you install the new "SP2" rollup, then all of those previously hidden updates will be installed.

The new "SP2" rollup can save time when doing a fresh upgrade from Windows SP1, but (in my opinion) the value of the new "SP2" rollup is questionable for a Windows 7 system that is mostly up to date with monthly updates.

As far as the newly announced monthly rollup of non-security updates ... I do not see much value. I  have decided not to install non-security updates.

For those who do install non-security updates, they need to consider the benefit of individually installing each non-security update (which then gives you the ability to uninstall individual  non-security updates if one causes a problem) versus the monthly non-security rollup (which is all-or-nothing ... all non-security updates are installed/uninstalled with no ability to pick and choose which non-security updates you want).

Some telemetry updates seem to kick in even for those who have opted out of the CEIP or similar MicroSpy programs, despite descriptions that suggest otherwise. In addition to checking for such updates, it's also a good idea to check every Microsoft/Windows process in the Task Scheduler. I have found (and disabled/removed) many active in both W7 and W8 machines that had "opted out" of any telemetry-based activity.

In response to my posting this morning - I was away from my computer yesterday, and I had not read any news feeds before I had posted this morning.  I then looked at my inbox, and I read a news feed article about the Windows 7 roll-up.  I have downloaded the roll-up, and I will install it as soon as I have finished my research.  I did download the (somewhat useless 3125574.csv file, which tells me which files are to be updated but does not tell me the individual fix IDs.  The spreadsheet has 250,587 lines and 21,750 names of changed files.

As far as I can tell, this roll-up will not ship patches that have been released via Windows Update; it does not re-release the nagware patches.  It does release all of the non-WU-released patches so that there will be a more current Windows 7 base on which to install Windows 10 (if the user wants Win 10 installed).  I do not know the internals of the Win 10 in-place install, so I do not know what in the roll-up might affect the Win 10 installation, which over-writes the Windows 7 installation.

These are all of the "telemetry" updates that I have confirmed either through research or personal observation. Not to say there aren't more, but it's a start.