that would be a really cool way to do it..... if mojang didn't put everything in their little change log so everyone with a youtube account and fraps can make a video about it. The snapshots are nice, don't get me wrong, but if they want to be like "you find out through a painting, mysterious!" then they can't just let everyone know about it before the actual release.
IMO finding out through a special painting and having that crazy boss spawn on you when you don't expect it, then going back to fight it in mega gear is a lot cooler than just finding out through a video or a change log and then having it instantly bound to your memory.