Ok, maybe it's not the best deck, but it's certainly the most awesome. From the pro tour this weekend:
To start with, the deck plays like your usual midrange deck; it grinds out incremental card advantage by trading up creatures with it's Birthing Pods. Start with a Wall of Roots, Take it's mana and sacrifice it with the pod to get a Kitchen Finks. Next turn, sacrifice the Finks to get a Murderous Redcap. For the investment of a wall and four mana (three if you don't count the one the wall produced) you get: 4 life, a 2/1 creature, a 2/2 creature and two damage to direct to any source you'd like. Next turn you can sacrifice the redcap to get a Reveillark or something. You're getting a lot of value for your cards. So even if the deck didn't engage in any other shenanigans you'd have a shot at taking your opponent down.
But does it engage in other shenanigans? It does. Oh yes it does. Take a look at Melira. Then read the fine print on Persist. Persist checks if the creature has a -1/-1 counter on it. If it doesn't, then when the creature dies it comes back, and persist puts one on. But if Melira is in play, then your creature can't have the counter put on it. So it comes back, but without the counter. So if it dies again, then persist will bring it back. Again. And again. So if you set up a Viscera Seer, for example, then you can keep sacrificing the creature and bringing it back over and over and over. To recap: Melira + Finks + Viscera Seer = Infinite life. Melira + Finks + Viscera Seer = Infinite direct damage. And if you've got the Finks combo, the Seer's scry ability even lets you find the Redcap.
So, in addition to the already solid midrange deck, you've got an infinite combo that doesn't even require bad cards to pull off. (Viscera seer is questionable on it's own, and Melira sans combo pieces really is only good against the combo poison decks that showed up, but finks and redcap are fine creatures even without support). Granted also that you've got effective tutoring methods (two different ways to search creatures into play) you can stuff your deck with all sorts of random creatures as answers to particular problems. It also gives you space to tune your deck for particular metagames. I can see how this deck went 8-2 in the highest level Magic tournament out there. (I presume Mr. Jaklovsky also had something to do with it).
Still, if I were to build the deck, (and you can darn well bet I will, soon as I get my hands on some more birthing pods) I think it'd be a little more... silly. To wit, there's another combo that you could easily shoehorn into the deck, but which Mr. Jaklovsky delclined so to do. Probably this was a deliberate choice tuning, which makes the deck more efficient, and therefore more likely to kill. But I'm too happy with the notion of the combo to dismiss it entirely. It uses Viscera Seer and Reveillark, which are in the deck already, to set up a stable loop with Saffi Eriksdotter.
Have Saffi, Reveillark and Seer in play. Sacrifice Saffi with her own ability, targeting Reveillark. Sacrifice lark to the Seer. Bring back two creatures with lark, one of which is Saffi and the other is up to you. Saffi's ability resolves, and brinks lark back from the graveyard to play. You're back where you started, but now you've got another creature in play. What that other creature is gives you a wealth of options.
Acidic Slime lets you destroy all their noncreature permanents.
Eternal Witness lets you return your graveyard to your hand
Tidehollow Sculler lets you force them to discard their hand (there's a trick to making sure the cards stay removed from game; it involves stacking the triggers properly and sacrificing Sculler again quickly. I'm not going to explain it here)
Wall of Roots lets you generate infinite green mana
And, of course, Murderous redcap can kill them and all their creatures in play.
Those are just the options that are already in the deck. Some more options:
Mulldrifter lets you draw out your deck
Elvish Pioneer lets you play all the basic lands you draw that way.
Nevermaker allows you to put all your opponent's permanents on top of their library
Merrow Witsniper lets you mill them all into their graveyard
Offalsnout lets you remove their graveyard from the game
Riftsweeper (along with Mulldrifter) gets you back anything that has been exiled
Siege-Gang Commander gives you an army of goblins
Essence Warden gets you infinite life
If you're keeping track, that allows us to draw all the cards in our deck, get back anything in the graveyard or that's been removed from the game, play out all our basic lands, play out anything in our deck that requires green mana, make infinite goblin tokes, kill anything your opponent has in play, or stack it on the top of his deck, mill his deck away, rip his hand, and exile everything in the graveyard. Leaving you with everything you could possibly have in play, a hand stocked with whatever you like, infinite life and mana, and leaving him with no permanents, no deck, no graveyard and only a couple land in his hand.
Furthermore, if you consider the Eternal Witness options, you can get back and replay any spell any number of times. For example, a Desperate Ritual played again and again gives you infinite red mana as well. Theoretically this lets you do even more things (rip those last lands from his hand, play out the nonbasic lands stuck in your hand, or possibly steal all his stuff) but I'm going to leave working out the details as an exercise for the student.
Or you could be boring, return a Murderous Redcap and just kill him. But if you do it that way, you'll never understand why Blofeld keeps investing in sharks and piranha traps.