I'm surprised this hasn't been getting more press -- in Telltale Games' Day 1 video from the San Diego ComiCon, Fables comic book creator Bill Willingham states that the upcoming Fables game storylines will be "in canon"; that is, part of the series' official continuity.
This is a pretty rare thing for game adaptations -- Telltale Games historically has become very good at creating stories that fit into existing universes without impacting them in any significant way, but it always makes the games feel like second-class citizens. To have Willingham onboard and treating this story/these stories as canon may allow for some more interesting and/or significant developments.
The closest example I can think of in adventure/comic book game terms would be the Scott Adams QuestProbe series done with Marvel in the mid-80s -- but even there the Chief Examiner seemed to get revised a bit as the series went on, morphing from (I maintain) Scott Adams himself in the first game to a more generic character by the third. The fourth game was never published, but the tie-in story did appear in an X-Men comic book later on, so I think the whole Chief Examiner storyline counts as Marvel canon (to the degree anything can in the ever-mutable world of superhero comics.) But the storytelling in those games was pretty simplistic -- navigating Spider-Man around inside an office building for the entire duration of the game and forcing the Hulk to solve puzzles never quite felt right; even if the related comic book stories are official, the games themselves don't necessarily deserve that status.
So this is potentially something new under the sun. Perhaps the Fables universe, with its myriad characters, just has so many story possibilities that Mr. Willingham feels comfortable calling the game canon without feeling like it will limit future developments. But I'd like to think his statement expresses sincere confidence and trust in Telltale's ability to treat his world and characters with integrity, respect and honesty, something the company has been able to do very consistently with their licensed games in the past.
Time and results will tell the full story. But I look forward to seeing how this one turns out.