Scrolls, the collectible card game in development at Mojang, will soon be in closed alpha state and once stable enough will switch to a purchasable beta. The alpha will have AI opponents, allowing for the single player to test out his decks, but it won't include the campaign mode, a world through which the player travels, picking fights to add new cards to his/her collection. Scrolls' website has also been updated with the first footage of the game in action, which makes me think of a cross between Magic: The Gathering, HOMM and a two player version of Plants vs Zombies without the zombies or plants. It does seem to have tracks onto which creatures and powers are summoned though, and idols to defend at the end of those tracks. Watch it below.
The post-release plans are extensive, including tournaments and online trading, although maybe referring to an 'auction house' isn't the greatest idea at the moment. It also sounds like the 100+ cards in the game can all be found by playing, using gold earned through victories to buy them or through the single player campaign, but purchasing also provides a 'free subscription' that provides a new scroll every week.
Once we've had a shuffle through the cards we'll find out exactly what all of that means in terms of plans for exchanging cards, building collections and post-release content. My fear of being constantly bested by more dedicated and knowledgeable opponents might lead me to wait for a single player mode with some form of progression and narrative before I really dig in.