Also keep in mind, everything is growing and changing rapidly. It is all still in its adolescence. All it takes is one solid whitepaper which seems to come out every three to six months that opens drastic new possibilities for solutions. Things start abstracting from other ideas, new concepts are introduced by new projects -- It's hard to say where Bitcoin itself will be in a few years as far as contract and scripting potential, and how much of this will be facilitated by other layers. Asset Systems, "Colored Coins", Sidechains, parallel AltCoins, projects like Ethereum, Bitshares, various dApp platforms -- all influencing eachother and the ecosystem...

But to at least partially answer your question, yes the current meta for design is that the currency tokens itself funds the contracts, providing a self fueling ecosystem.