Last I heard, Mastercoin is just a specification. It's too early to pretend it's going to work. I heard an interview w/ the author and it sounds like lots of talk and big dreams w/ no real technology to back it up. When asked how long it will take to release a working prototype, I think he said two weeks if he gets enough donations to quit his job. OK suuuure. You can find the interview on YouTube. It's almost comical.

As far as "Colored Coins" looks like the same scenario--just an idea for a protocol? Their video is vague, doesn't really explain anything. Bitcoins backed by car titles? Let me guess, a decentralized vault full of luxury cars nobody can drive? LOL. http://coloredcoins.org/about/our-team/