Gaming and blockchain are a match in more ways than one! Like you say the microtransactions and paid content will play a big role for starters, but I think the whole model might change.

Of course we know pay-to-play, and you mentioned the freemium model as well. But I think with blockchain underlying games, we might even see a new model arise: Paid-to-play, which similar to how Steemit works, doesn't cost money but actually pays the player for playing the game.

How it would work best I'm not sure, there are multiple ways, from mining in minecraft-type games to just finding loot on monsters. I think there were already gold-farmers in games like World of Warcraft, but it's going to be insane in the world of tomorrow. Who knows, jobs might actually migrate to online virtual worlds... instead of chopping down trees in real life, we will be chopping down trees for lumber in minecraft games, to sell to virtual consumers? If virtual money has value then perhaps virtual lumber does too.