the new aggron *censored: not good*, 90 damage for 3 energy (on a stage 2 at that) isn't nearly so overpowered that it needs to be balanced out with a 25% chance to miss. and 3 cards off the top of your opponent's deck is kind of weak considering it's a one-off on a stage 2, when there are basic pokemon that can do that repeatedly.
the new scizor isn't great either, because most every deck uses pokemon catchers, which completely bypass those kind of defensive abilities that are only activated on an attack.
i won't argue that cobalion isn't great, i mean it is. it's one of the few, and also being a basic, it was cool being able to stack special metals on top of an eviolite.
new registeel EX is alright. doesn't really stand out, though, and again, the defensive ability is tied to an attack, and can be easily bypassed with a catcher.
you want to see a metal card that i *am* excited about? check out the team plasma klinklang they just unveiled as part of japan's upcoming BW7 Plasma Gale set. not only is it always immune to pokemon ex (instead of only after using an attack), it actually makes *all* your metal pokemon immune to pokemon ex. now that's the kind of defensive specialist metal card i'm talking about. now if only they came out with the metal equivalent to dark claw, maybe "metal plating", that reduces damage for any metal whether basic or evolved.