Earlier quoted context omitted.
Your Solidity contracts can run on Ethereum Classic, which you can be confident won't be forked since its users tend to believe in the principle of the immutability of the code.
The classic branch is still susceptible to the same problem, though. They didn't fork because of the DAO, but who's to say they won't fork because they don't like the result of a different contract? If I'm going to trust the enforceability of my contract to some group of people, I trust the established legal system--warts and all--much more than the mob rule of the Ethereum crowd.
So is bitcoin.