So, once again a new set is coming out and the staples list needs a look at again.
I'm not sure how alive this thread is anymore, so we'll see how it goes down.
Aetherize : This is a card that may not be massive, but will probably get played situationally in certain metas. In such metas it will be a very powerful card that will turn games around. Blue needs all the board wipes it can get, even if they are situational. However, due to the situational nature of the card I would consider this card as not worthy of the status of really good. Decent, but not that good.
Assemble the Legion : This card is probably too slow to have a major impact in EDh games. However, I have seen similar cards used to high impact, so there is probably a deck for it. Not a good or really good card.
Aurelia, the Warleader : Very powerful in her colours and probably the best RW general. Multiple attack steps are always nice, and if you have some kind of imeadiate blink repeatedly it goes infinite. She is powerful enough in her colours to be really good.
Biomass Mutation : Game ending x spell in UG. I would consider this as really good, given how powerful Mirror Entity is. Green likes having at least one card of this type.
Biovisionary : Combos with Rite of Replication . Not a good card, but decent in combo. Decent.
Clan Defiance : It's not comet storm. It's good, but it isn't comet storm. I think that's the best summary.
Consuming Aberration : Heh, this is a Lord of Extinction that grows itself and has an alternate wincon. Downside: it helps your opponents as well. I'm not sure how good this is. It could be amazing, or it could be really meh.
Crypt Ghast : Auto staple in mono-black. Flat out auto-staple. In two and three colours it is still decent, especially with urborg.
Domri Rade : Slow, doesn't quite combo with doubling season as well as I'd want him to, but can win the game the same way akroma's memorial can. However, with memorial you often have a surprise factor. This is decent.
Enter the Infinite : Should win a blue deck the game on the spot. However, blue should be able to do without this, generally without the massive risk factor. Good, not quite there though. Awesome card though. I expect many blowouts to this.
Foundry Champion : Given the blowouts that have happened in my meta due to Rakdos Charm, I would not be surprised if this sees play. However, it is a little winmore. Will almost certainly be around, so watch for it.
Giant Adephage : Heh, Timmy likes. Not competitive, but can run out of control easily, which will then win the game. It won't see play in any of my decks, but only due to the prevelance of board wipes. Meta dependant. Big green and stompy decks will like it.
Gideon, Champion of Justice : I've seen a couple of people going "really good in EDH" online, which I think is horribly wrong. This card isn't particularly good in EDH. I don't like him and can't think of anything I'd cut in any deck to put him in. He just seems a little unfun.
Glaring Spotlight : Now this, this needs to be considered in detail. It shuts down quite a lot of bad things in metas, and is quite good hate. It is hittable with Trinket Mage (always a large plus), and can either give protection or game winning swings. It can also end stalemates like a boss. All in all, I really like this card. Really good at least.
Hellkite Tyrant : This is an amusing card, and everyone realised the combo with Mycosynth Lattice the moment they read the card. The only problem is, is that this will prevent it from being used in a more useful way; stealing mana rocks would have never been easier. I like this card. Not sure if it is quite really good, but it always needs to be answered. Similar to Lighthouse Chronologist in useage, methinks. Kill or die.
High Priest of Penance : There will be indestructibility shenanigans with this card. Someone will do it, and your job will be to disable it (unless you are the one doing it, like I intend to be). Not quite really good, but definitely really annoying.
Illusionist's Bracers : It's like Rings. It's very like Rings. And just like Rings it doesn't quite make the really good slot in my opinion. It will combo well, somewhere.
Immortal Servitude : I like this card, so I'm disappointed that I think it won't be good in basically any EDH deck. I can see a case for x = 2 or 3 in some decks heavy in utility creatures, but usually a single target reanimation is going to be more useful. However, I'm ready to be proved wrong on this one.
Lazav, Dimir Mastermind : Unfortuneatly, he's competing with some tough customers in UB, including Oona and Dralnu. Fortuneatly he's one of the best clones UB has IMO, and so he should see lots of play. I expect him to be really good.
Lord of the Void : Big, stompy, fun. Not good, but fun. Will see play.
Luminate Primordial : Swords to plowshares on a decent body? Swords to plowshares on a decent body?! SWORDS TO PLOWSHARES ON A DECENT BODY WITH ETB EFFECT?!?!?!? Okay, so not quite that exiting, but I think it straddles the boundary between really good and staple in less competitive white decks. That level of removal is insane in late games, and it is in one of the two good blink colours.
Master Biomancer : I really don't know how to evaluate this card. It will see play, but is it decent, good, really good or staple in its colours? I'm really not sure here. Time will tell.
Merciless Eviction : Final Judgment is nothing to this. Truly insane.
Mind Grind : I know it's mill, but wow IT IS MILL. Seriously, this puts a metric ton of cardboard into the graveyard. It shouldn't be considered for this list, but it will see play in dedicated mill decks. It will ENABLE dedicated mill decks. It... just wow.
Molten Primordial : Seems like a very decent creature for red. A 6/4 haster that nets you creatures equal to the number of opponents to hasty swing with. Act of treason for each opponent. Yep. Good card. Certainly a staple for later game mono red decks.
Nightveil Specter : I'm not qutie sure how this one will play. If you are in a blue dominated meta then this will be quite strong, most likely. Especially for only 3 mana.
Prime Speaker Zegana : I'm not quite sure I like her. She's probably very powerful, simply for the card draw... it just feels a tad winmore. I expect that she'll make a very overcommitting general. Good.
Rapid Hybridization : See all opinions for Pongify ; good for monoblue.
Realmwright : Strong mana fixing in a colour that normally doesn't have it. Decent.
Sepulchral Primordial : This card... black likes... everyone likes. This... just... what? Really good at least.
Signal the Clans : Decently cheap tutor, especially if you have semi-redundant creatures. RG likes a lot. Probably really good.
Stolen Identity : When I first saw this card I thought it was a bit meh. Now that I'm looking at it again I'm not so sure. Possibly one of the only good cipher cards for EDH. Maybe good. Somone else evaluate it.
Sylvan Primordial : What is it with these primordials? They're all amazing in EDH. Really good, especially with Prime Time missing.
Thespian's Stage : Staple or Really good. This card is a debateably better Vesuva, and Vesuva is in most decks that can afford it.
Treasury Thrull : Good recursion and extort, while mostly irrelevant is a nice addition. The only problem is that it is on attack, rather than ETB, but hey, not all our goodies should be ETB effects.
Undercity Informer : Yet again, mill. Thanks to large mana pools and many token generators, this can actually kill very quickly. It can also self mill. And it's a sac outlet. Actually, this card is bonkers. Love it. Really good.
Vizkopa Guildmage : This card... I like it. If you swing with lethal and 6 mana open you've won. Blocking basically doesn't matter. You just gain enough to kill them. Double your life total? Win. Random decent life gain? Win. And it's each opponent. Our favourite card, Exsanguiate? Ouch. Dedicated lifegain in WB needs this card. NEEDS. Very strong, likely really good.
Whispering Madness : Windfall that can be repeatable. I like this card a lot, but I don't think it is actually massively good. Certainly strong though.
Zameck Guildmage : Again, a very powerful guildmage in EDH. Note that his first ability can be activated multiple time and stack. Strong, but not really good.
Hope I caught the ones that are going to see some kind of play at least in EDH.