Well, more and more, I see the biggest problems being Dimension Fusion, and Return from the Different Dimension. I don't even see Dark Armed Dragon as big of a problem as those cards. With all the draw power, it makes searching for them just that much easier, but totally take away Dimension Fusion, and then either take away Return, or drop it to one, and both DAD and Allure lose a lot of their oomph.
Darklord Zerato, while definitely good, is usually only ran at one in a deck anyway. Without as much mass swarm capabilities, the deck is slowed down a good bit, dropping DAD down to 1 would definitely make a lot of people happy, but it's just one key in the whole puzzle. If you look at a lot of the decks, they can often win without DAD ever being played, so curbing the "mass revival" cards are the big issue right now. It's just as easy to bring back from removed from play, now, maybe even easier, than the graveyard.
Darklord Zerato, while definitely good, is usually only ran at one in a deck anyway. Without as much mass swarm capabilities, the deck is slowed down a good bit, dropping DAD down to 1 would definitely make a lot of people happy, but it's just one key in the whole puzzle. If you look at a lot of the decks, they can often win without DAD ever being played, so curbing the "mass revival" cards are the big issue right now. It's just as easy to bring back from removed from play, now, maybe even easier, than the graveyard.