I'm being offered KB2952664 on W7 "to improve the upgrade experience".
Sounds like the same sort of thing.
Incidentally, does this happen to you both too?
W7 knows that it's W7, hence it selects the W7 WUDs, but if I click on "details" it seems suddenly to change its mind and decide I'm really XP and in the wrong place !
Not that one. I don't seem to have it and when I Google KB2952664 I get the proper page at MS telling me that I should get it from WU. I wish they would also give a direct download link as there usually is one.
I often get those pages telling me that this is for a different system, I think it's their website at fault and/or cookies.