The first three images are wallpaper by black crow studios. I'm sure it's probably really expensive and the repeat has to be something insane. The website is worth a look, though.
I like the idea of doing the watercolor on the walls yourself like these examples: I don't know how difficult the process is but it doesn't seem like it would be too bad - other than being really messy trying to keep the walls wet. I'm sure you could water down regular latex paint slightly to achieve the look.
Hmm, I just may have to give this a try!