Well, the next update, due anyway now is the 2-player background queuing system, global chat, etc.
After that we plan a small update that will include 2 new cards per faction, that are unlocked for winning a number of 2-player and 1-player games. This is not such a big update so I hope that won't be too long.
After that will be the next faction. The cards are designed for all the factions, the art is not.
Choices for next faction are: mountain (barriers), ice (auras), desert(items). I believe Mark is interested in drawing the icy stuff next.
(There are at least 2 more factions that will follow on after those 3, one of which has a new map area..)
We all got tied up with other projects earlier this year, but at least this update is coming soon. It was a big thing for us ,as we really want to encourage 2-player. The current (old) system doesn't help, as if you want to queue for 2-player that's all you can do. At least soon you can being in a 1-player game, or designing a deck as you wait.