Did Voyager 1 Leave the Solar System or Not?

Sarah Scoles, writing for Discover Magazine:

The thing about crossing into uncharted territory is that you may not know when, exactly, you have crossed into it. No one needs to tell that to the Voyager 1 spacecraft, which is currently at the center of a controversy about where the solar system ends and interstellar space begins.

A nice, sober look at the debate.