I think it will be eerily similar to 8.1 just like 7 was to Vista. I think it will get the same praise that 7 got over Vista as well even though they are basically the same OS.
As far as new features go I think they will be few and far between. 9 will most likely use the same kernel that 8/8.1 does just with a more refined UI.
However, it would be nice to get multiple desktops! It would be really nice to have one virtual desktop for editing photos, one for work, one for play, etc... Hopefully the implementation is going to be good.
I think they are going to make you buy it if you want DX12.
I think windows 9 will be a renamed windows 8 lol i don't need DX12 or DX11 really don't need to upgrade. my windows 7 computer for DX11 and windows xp with very good anti virus will keep me online until 2020.