It's too late in the day for anything but an explanatory headline. I was going to go with 'Steam Punk' because 'indie development = punk' but then I realised that was utter nonsense so I decided not to. Here is the news, straight from the IGF organisers: "All IGF Main Competition finalists for this year's event will receive the opportunity to accept a distribution agreement for Steam." The IGF hasn't made distribution agreements on behalf of developers though, with the final decision as to how the finalists reach the public still in the hands of the entrants. Instead, this route appears to be a means of avoiding arcane normal submission procedures or Greenlight.
This seems a decent way to give worthy games extra commercial exposure, although I'll probably wake up tomorrow and discover that half of the internet thinks it's a cunning ploy to destroy independent development once and for all.
Finalists in each of the categories, all of which are covered by this agreement, are due to be announced in January. Last year's winner of the Seumas McNally Grand Prize was Fez, so let's hope they make this deal retroactive and work on bringing that to Steam, eh?