Intro packs, event decks and duel decks have a fixed deck list. It would save much work for the user if they could be added at once instead of adding each card individually. So for example if one buys the Innistrad Event Deck "Hold the Line", the Duel Decks: Ajani vs. Nicol Bolas or the Magic 2012 Event Decks Illusionary Might and Vampire Onslaught they could be easily added to the inventory as it is known of which cards they constist of. Especially as the Duel Decks are already part of the database, the only thing missing would be the number of cards of each card type.

There is an other feature request that points into a similar direction but is much more generic and difficult to implement. Feature request #122 (import decks into an inventory) would be even better but I can see that there would be many problems in detail. Thought a deck format that would allow to specifiy the edition (and kind if necessary) of each card might work.