Played about 6 games of DOTP2012 and already encountered a problem with assigning combat damage. I had a creature which dealt 7 damage. 4 went to the creature with 4 toughness. With the remaining 3, it could have gone to a 2/3 creature or a 2/2 creature that was unblockable. I would have killed the 2/3, the computer targeted the 2/2 unblockable, which technically can be seen as a greater threat. Considering I had a couple 2/2's on my side, I wanted to see the 2/3 killed. Like the landtapping, it was an annoyance, but not game breaking, as I won the game anyway.
Also saw another problem with the game. You can't do things that seem illogical or that would appear to harm you. For example, I ran into a blue deck which had a 4/5 creature which had to be sacrificed if it was the target of a spell or ability. I tried to Giant Growth it, but couldn't target it since GG is considered a 'friendly' spell. In the previous game, you could target yourself with harmful spells or Giant Growth an enemy. It was previously an option to toggle, but now that option is gone.
Despite these annoyances, the game feels a lot better than the previous one. The cards are more powerful, the game plays faster, and the deck editor is awesome. It shows your mana curve during construction, and playing with a souped up 60 is a huge improvement. I had trouble deciding what to cut at one point.