Can you choose your own wallpaper on Windows 8 start screen?

Is it me, but in the ads and Windows RTM there is no way to choose your own custom wallpaper on Windows 8 start screen? I dont want to be stuck with a solid color background. Or none of the ugly tattoo wallpaper. I like to change wallpapers depending on my mood. But I never tend to feel purple or orange or blue or peach. Can anyone tell me this will change with the release?