As noted in the Paradox Interactive Forums, a new patch is now automatically available for Magicka, addressing some issues in the action/adventure/RPG and paving the way for the newly released Dungeons and Daemons DLC for the game. This page shows where to buy the DLC, here's a launch trailer, and here's the pitch for the new content:

Something stirs beneath Castle Aldrheim…

Deep in the sub-dungeons, long forgotten by the Wizards, the demented ancestors of the Aldrheim Order have awoken an ancient evil. The fate of the world has yet again fallen on the shoulders of our haphazard and colorful wizards. Will the Wizards survive as they stumble upon Aldrheim’s most secret of secrets?

Explore never before seen places in the fantastical world of Magicka. Test your mettle against new enemies and try to avoid getting slime all over your robes. Where does that even come from? It’s everywhere! If we could reveal the super-secret hard mode, it would attract even the most battle-hardened wizards. Unfortunately, it’s a secret, so we can’t talk about it.