Why would you want to use a separate blockchain when you have an existing, extensible technology? All these kind of "projects" will give bitcoin more worth and intrinsic value.
Use the existing blockchain for EVERYTHING - it makes it more powerful actually if everyone is involved with everything.
I don't get how smart contracts working on top of Bitcoin (but not being Bitcoin themselves) will give Bitcoin “more intrinsic value”. Bitcoin is already worthy by its own merits. We don't need a savior project (or a “killer app” as these people like to call it, or whatever) to give Bitcoin value.
Also, about everything using the same blockchain... Well, it can be both. You can either use Bitcoin's blochckain for this, or create a new one (I'm not sure if that would be an alt coin or not). I guess it doesn't matter. It is just my opinion (and nothing else) that the blockchain should be exclusively used for money.