But we haven't seen it. The press has. Not the public.
I know that's what I mean. If they show it at E3, or if it gets shown before the release it's not going to be that fun playing it in game (for me anyways). Now I don't claim to have knowledge that they will show it before release, but it does seem to be the demo they're sticking with.
[edit] Also, if I had known about the paintbrush quest before having played it myself I think it would have been less special. One of the things that I loved about that quest was that it was so random and it had no ties to anything else in the game, it was just there in the gameworld for you to stumble across.