This is a simple deck that is specifically designed to hold back creatures through lots of counters and bounce spells. Aetherling is the finisher. The sideboard is mainly designed to give you more useful stuff in the event that you're playing against control Suggestions for the sideboard are definitely appreciated, as I'm not entirely sure how to control control.
This deck should be particularly effective against tokens (Selesnya, Goblins), +1/+1 counter decks (Simic, Golgari) Mill decks (Dimir) thanks to Archaeomancer, aggro (Boros, Rakdos, Gruul, RDW), and mono green. Its weaknesses are likely other control decks (Orzhov, Izzet, Azorius) and decks light in creatures (Izzet).
It is the deck I plan to build after Standard rotates, which is why you see no Innistrad, and changes will likely be made as more Theros and M14 cards are revealed.
6/4/13: I tested this deck online for the first time against a Gruul deck. The game was very long and I went down to 4 life eventually, but it was successful. It took so long because I had to draw 37 cards before I finally drew AEtherling. But I did defend pretty solidly.
6/5/13: I gave my friend my RDW deck and tried playing this against it. I was able to hold him off for a while, but I failed to draw AEtherling and eventually lost. RDW shouldn't be nearly as effective after rotation though, with things like Hellrider gone. I also played another match online against a black deck. The extort in the deck caused me to die. Rapid Hybridization may be a good thing to add or at least sideboard.
6/6/13: Another online match, this time against a wolf deck. Took a very long time, and I thought I was going to lose, but I ended up winning. My opponent was playing smart, attacking with just one or two creatures at a time because he knew of my AEtherizes. But then he made the bad decision of attacking with everything, including several wolf tokens. I AEtherized it all, he had to discard some stuff. Then he replayed his Huntmaster, and I countered it, and quickly brought him to 0 with my AEtherling, which was already out. Before that though, things were looking bad because of mistakes I made, including not countering his Huntmaster earlier when I easily could have, and forgetting to cast Inspiration at the end of his turn. I also played against an Orzhov deck. He didn't really seem to be doing much, but he ended up forfeiting because he had to go. I also played a complete newb, who almost beat me because I had to draw 47 cards before I drew AEtherling. Then he prolonged the game a few turns more with Bountiful Harvest, and Lava Axed me twice. But I won after that.
It's difficult to explain everything on how a control deck works. Generally, I use the Unsummons and Cyclonic Rifts to bounce stuff in the early game, putting them a few turns behind. But remember that in the late game, you could use the Unsummons to return an Archaeomancer and put it back down to return a more effective bounce spell, such as AEtherize. I also use Essence Scatters and Syncopates to counter creatures in the early game. If you have the choice, it is generally better to Frost Breath creatures than bounce them. This just holds them back a few turns, and then they may end up putting down more creatures, making AEtherize and Cyclonic Rift more effective. When bouncing a great many creatures at once, you can force them to discard stuff, creating some awesome card advantage. The Divinations and Inspirations are of course to draw cards to find more control spells. Archaeomancer acts as a blocker so that you may not have to waste a bounce spell, and more importantly, gets an instant or sorcery back. Archaeomancer has proven to be very helpful in this deck.
Another trick you can do is bounce a creature, and then counter it if they try to put it back down.
Then, at a moment when you have around 8 or 9 islands and have complete control at the moment, you can cast AEtherling. Don't cast it with just 6 islands on the field; you need to have some mana open for spells and to exile it if it's targeted. Then attack with it and proceed to win. By the way, remember that you can exile it after attacking so that it's untapped. That way it acts as a blocker.
For sideboarding, you're going to want those negates if you're playing against any deck that's light on creatures. However, you shouldn't have to worry about token generating spells, because they can easily be handled by AEtherize or Cyclonic Rift. If they are using Assemble the Legion though, things could go very bad if it isn't countered. If this is the case, Negate may be more effective than Essence Scatter.
If the games are taking a long time and you have plenty of mana open, Opportunity is a good spell to have around. If the game is long because you're playing against control, you should include Dispel to prevent important things, such as AEtherling, from being countered. You can of course also use it to counter major spells such as Sphinx's Revelation or Advent of the Wurm.