We are taking the development of MTG Arena extremely seriously. (magic.wizards.com)
The focus of MTG Arena will be on the newest cards and game modes. (magic.wizards.com)
There are two types of packs players can get in MTG Arena: booster packs, which contain eight cards, and Draft packs (packs you get in Draft events), which contain 14 cards. (magic.wizards.com)