Again, since the screenshot mentions “early design and not the final UI”, we can at least expect full screen wallpapers to be there in Windows Mobile 10, that will be independent of tiles and will be system wide. Though, I would personally prefer the how the transparent tiles appear now on that wallpaper. May be Windows Mobile 10 comes with option of transparent / colored opaque tiles.
Thanks trnz for the tip. Watch the video below and seek to 26:06.