DotA 2 - F2P

In a recent podcast, Gabe Newell stated that DotA 2 will be free to play, but with "twists". Although these twists were not talked about, he claims that it is totally unique from any other free to play mechanism; something that has never been done before. What do you guys think the "twists" could be? If it hasn't been done before, then I don't think it's just modeling after free to play mechanisms in League of Legends, where you can use in game points or real world money to buy characters/skins.

Full article: http://gamingbolt.com/gabe-newell-dota-2-is-going-to-be-free-to-play-itll-have-some-twists

Alternate question for discussion, should this influence DotA 2 Beta giveaway prices? I already own the beta, so I'm not biasing my thought in any direction. Just some food for thought.