Several of my friends have started playing a game called Warstorm on facebook, and I've been getting lots of messages about them giving each other hunters and mages. I decided to try the game today. My impressions have not been very positive.
It's a CCG about fantasy armies battling each other. The battles themselves seem to be completely non-interactive. Your cards are drawn in random order, and after being in your hand for a number of time steps (the 'cost' of the card) they enter play. No decisions are made during battle. So basically, the entire game is about deckbuilding. This is (like Dominion) a game designed to attract ex-Magic players who get nostalgic about deckbuilding, regardless of depth. But it's combined with the money-sink of actual CCGs (you can get new cards by investing time, but the cards that cost real money on are strictly better) and the social addiction of Farmville. A charming mix. Plus the UI is laggy and the game has more fun than the player. I don't recommend it.
(It's a pity, because the mechanic of having a card's cost be the number of turns it takes to enter play after drawing it is quite elegant.. unfortunately what it elegantly achieves is nil interaction!)