While we do love Windows 10 ourselves as a desktop OS, the player works just fine with older versions of Windows so there's not particular reason to upgrade.
However, Microsoft has enabled a default download, and some say a possible future automatic update through the Windows Update of Windows 7 and 8.x.
This means that many of you who are running with Automatic Updates enabled could get messageboxes on your screens in the future. Our Monitor WatchDog will take care of this, but a forced Windows 10 upgrade will be more difficult to handle.
We'll update you as soon as we get more confirmation on this!
More information here: