To nobody's surprise, Deoxys' Leaf Green and Emerald forms were banned with a near unanimous verdict. Can't really say I'm surprised, those guys were exceptionally good at what they did, which not only includes setting up Stealth Rock but also mess with opponents further with screens and assorted stuff, since they have enough defenses/speed to do it.
So that means next up is Aegislash. And while there IS some debate going on, it seems to me like it's going to have to pack its bags and leave soon. The big problem here appears to be King's Shield's added effect, which greatly reduces the amount of moves you can use to damage it without crippling yourself in the process. Some Pokémon would LOVE to use moves that grant more coverage, but are forced to use Earthquake just so they can deal with Aegislash, such as Mega Pinsir with Close Combat for example. And it pains me to say it, but keeping aside two or three moveslots out of 24 JUST for Aegislash is the perfect illustration of brokenness. Of course, the ability to swap between 150 attacks and 150 defenses at will (while being so slow happens to be beneficial, no less) is also commonly cited, but if King's Shield didn't screw over contact move users not named Bisharp, it just might have been okay.
It's also been suggested that giving Aegislash the axe would single-handedly make threats it dealt with dangerous enough to be given their own suspect test afterwards. However, Smogon's official policy is "we'll cross that bridge when we get there", so if they have to test a half-dozen Pokémon just because Aegislash is gone, so be it. A few people who gave their impressions on the suspect ladder claim it's not as likely to happen as previously thought, however, because of the sheer amount of Talonflame spam.
Regardless, it saddens me that for once we have a Pokémon with a cool gimmick that's actually viable, and we're going to lose it because it's just that damn good. *sigh*