The website says that Blizzard has declined to comment in an official capacity, and the site's source could not provide more details. It's been speculated that World of Warcraft's recent subscription losses, the fact that DOTA is free-to-play, and the game's unlimited free trial though level 20 all indicate a shift in Blizzard's business model mindset.
COO Paul Sams also paid lip service to F2P at BlizzCon last October, saying that F2P "certainly is possible, if we find ourselves in that circumstance, or if we come up with a game where we think that's the right business model, the most appropriate for players to experience it."
Could the long-awaited Project Titan MMO be Blizzard's first F2P offering, or is a completely new title in the works? We'll update you as the story develops.