My Manaless Dredge build has evolved over time, and for a while was pretty close to Hollywood's build (http://jupitergames.info/articles/2012/52180/the-cutting-room-floor-manaless-dredge-in-legacy). However I've made some changes since Gatecrash hit to make the deck feel more like my own.
Manaless Dredge Primer: Opt to play second to get the draw. Use the clean-up step to discard a dredger into the graveyard (ie. Golgari Grave-Troll , Stinkweed Imp , Golgari Thug , or Shambling Shell ). Then, each draw, dredge instead, using Street Wraith to accelerate and Phantasmagorian to dump your hand into your graveyard. Dredging allows threats like Narcomoeba , Ichorid , and Nether Shadow to pop into play for free, with Bridge from Below netting you 2/2 tokens whenever your creatures die.
How to win: There are two basic ways to win, first is beatdown: each Ichorid can swing for 3 per turn, and self-sacrifices at end of turn giving you a 2/2 Zombie for each Bridge from Below you have in your graveyard. This puts your opponent on a very short clock, and in some matches, allows you to cruise to an easy beat-down victory.
The second win condition is anything from the set of possible win conditions enabled by Dread Return : Optionally you can begin by Sacrificing something to flashback Cabal Therapy to try to remove counter spells from the opponent's hand. Once in the clear, Sack three to Dread Return one of three possible this-turn-game-enders (dependent on what is available in the graveyard).
1) Dread Return : Balustrade Spy . When he hits, self target, and since the deck has no lands, his ability flips the whole library into the graveyard. At this point your options are limitless! Dread Return : Reveillark , sack it to Cabal Therapy to strip the opponent's hand of anything that may disrupt you ending the game, and off Reveillark 's leave battlefield ability, bring in Azami, Lady of Scrolls and Laboratory Maniac . Tap either one to draw a card and win.
2) Dread Return : Griselbrand , pay 7 life to draw 7 cards, dredge with every single one of them, filling the graveyard. Dread Return : Laboratory Maniac , use Griselbrand 's ability again to deck yourself for the win.
3) Dread Return : Flayer of the Hatebound , then Dread Return : Golgari Grave-Troll , dealing obscene amounts of damage, dependent on the size of your graveyard.
Versatile and explosive!
The sideboard is lands and disenchant to deal with graveyard hate, plus an Iona, Shield of Emeria to lock out Mono-Colored decks. Balustrade Spy and Land don't work well together, so when I board for hate I remove most of the components of the first Combo I mentioned and rely on Beatdown or being able to put grislebrand to work. I try to play around Surgical Extraction , Deathrite Shaman , and the like; I have so many threats that I can win through a fair bit of disruption. I primarily sideboard to deal with Leyline of the Void , and Rest in Peace . I've been happy with how it has performed so far, but it is still in early days.