I suspect that if TypeScript takes off that this will probably be crowd sourced, i.e. expect to see a ts-node project on github.

That said, I think they've done a reasonably good job of making it painless. Even if it weren't required, I quite like the idea of explicitly listing the 'global' dependencies a particular script has. I think it's going to make unit testing it more pleasant, i.e. because you declare the dependencies your script has, it's obvious what you need to mock out from the environment to unit test it.