New
#11
I first saw multiple desktops in Linux about 14 years ago but I am quite certain it was not new then. There have been third party utilities that brought this to Windows since at least Windows 2000. The Mac also has multiple desktops. Windows 10 is the first version of Windows that supports this natively. Functionality appears to be very basic and probably not finished. Microsoft has specifically stated that Windows 10 is not yet feature complete.
I have been using VirtuaWin with Windows 7 and find it convenient, particularly with many windows open. With only a few it is probably not worthwhile.
Multiple desktops have been around for a long time and many people use them routinely, some no doubt claiming they could not get along without them. But like many other OS features they are not for everybody.