Suppression Field

Equipment Killer, Sensei's Diving Top Killer, Fetchland Killer, Meanie activated ability creatures' (E.G.: Royal Assassin, Gilder Bairn, Triskelion, etc.)Killer... And on the + side you can run the new Training Grounds to negate it's affects towards your creatures if that's the route you go.

Slowing of the fetchlands is probably my favorite attribute of this card, especially since tourney and my play group all run lots of them -- Terramorphic Expanse, Evolving Wilds most common, although I love when they have to pay 2CMC and 1 life to get a land that actually taps for mana, lol!

umazawa's jitte killer!

Damping matrix is one of my all time favorite cards. I won alot of tournaments on the back of Damping matrix. People search for cards that have good activated abilities well now its time to make 'em pay... 2 mana more. This really can hurt the equipment cards including the very popular Umezawa's Jitte. Wana give my creature -2/-2 it will cost ya four mana this turn, need to re-equip that Jitte it'll cost them four mana. Suppression Field is an excellent card and really hurts if two or more are on the table.