When it came to Magic: The Gathering - Duels of the Planeswalkers, I was in the minority.The fact that I couldn't fully edit a deck never really bugged me -- I enjoyed the structure. So, for me (and I imagine a lot of you), the biggest question going into my Duels of the Planeswalkers 2012 preview session was how customization would work in the sequel.
It's still structured, but not so much that you can't play around with those initial 60 cards in each deck. While lands are set in stone, any other card in that base deck list can be swapped out for another -- outside of the restriction that a deck must be at least 60 cards, you're free to mingle cards in and out that fit the parameters of that deck (e.g. color and creature themes).