About the Windows 7 support expiration.
Win 7 may continue to get security updates.
XP did for at least a year.
Still a lot of Win 7 desktop users woldwide.
From here
Desktop Windows Version Market Share Worldwide | StatCounter Global Stats
I'm not able to get a graphic return on other years at the moment. It would be interesting to see US only as well as what XP percentage was when support was officially dropped.