does it do anything that Win 7 or 8 couldn't do?
Well, it has a new hybrid start menu that is pretty nice (menu + tiles, nicer than either 7 or 8's offerings); a really handy personal assistant thing (similar to Siri and Google Now);
massively improved Aero Snap (you can drag windows to any corner instead of just L/R sides, as well as it's easier to put something on the other side); a proper windowed mode for modern apps (that only run fullscreen in
; built in virtual desktops support, a pretty decent
notifications system to replace the irritating old notifications style; a built-in screen recorder in the Xbox app, which itself is a marked improvement over old GFWL nonsense; and a redesigned settings panel that doesn't suck like what Windows 8 had.
But perhaps most importantly, it has DirectX 12. Nothing uses it just yet, but eventually more and more games will require it, making 7 and 8 virtually useless for gamers much how DX10/11 made XP useless for gamers.