We upgraded at home a while back, and we just completed all upgrades at work. Non issue in almost all cases, and for those few that were at issue at work, we resolved all upgrade issues.
At work, it was a no-question decision, because all business-critical programs are Windows-based (Office, Dynamics AX, SharePoint, etc.) Non-Microsoft options are simply not in the cards for the foreseeable future. I'd love to see a transition to Open Source applications, but they just don't exist when it comes to several specialized applications we require.
At home, the only thing really keeping us on Windows is Quicken. We've used Quicken since DOS days, and we rely on it for managing our finances. Simply put, there are no truly comparable alternatives. And because we require that, all other devices really need to be compatible.
Yes, as a tech geek, I could adapt and come up with a nice alternative, but my wife is more of an "appliance user" when it comes to computers, so having different systems won't cut it. Making sure that the user experience at work is consistent with the user experience at home (which it is) is goal number 1.