"Indie" now includes "rockstar."
These five spoke at "Back to the Garage: The Return of Indie Development (From Those Who Were There and Some Who've Just Arrived)," and without specifically addressing the concrete idea behind what makes indie "indie," they helped define the term in its modern trappings. "Indie" involves listening to feedback from outside sources. "Indies" create AAA titles. "Indie" means talking to press, managing staff and marketing a game while respecting other people's time. "Indie" is about making money.
Being indie doesn't sound so different than standard publisher-style game creation, mostly because it's not -- indie is now a sub-genre of game development, rather than a separate enterprise. It's in the tone with which these developers speak about the business, their independent passion and the amount of risk they're willing to take that offers a clear distinction from the sterile PR BS often found in the campaigns from large publishers.