In case you don't follow the OCG releases, let's take a look at the new DW cards being released. These are the OCG card names and effects, since we don't yet know the English texts.
Grapha, Dragon God of Dark World
You can return 1 face-up "Dark World" monster you control to the hand, except "Grapha, Dragon God of the Dark World", to Special Summon this card from your Graveyard. If this card is discarded from the hand to the Graveyard by a card effect, select 1 card your opponent controls and destroy it. If this card was discarded by an opponent's card effect, look at 1 random card in your opponent's hand also. If that card is a Monster Card, you can Special Summon it to your side of the field.
An amazing boss monster! First, if it's discarded by your own effect, you can destroy any card your opponent controls. If it was discarded by your opponent, you also have a chance at stealing a monster from their hand. That's not all it does, though, as this card is very easy to summon. All you need to do is bounce a Dark World monster to your hand, and you can summon this card from your Graveyard. You then have a free 2700 beater, and another chance to discard the DW monster you bounced.
Snow, Magician of Dark World
If this card is discarded by a card effect: add 1 "Dark World" card from your Deck to your hand. If this card is discarded by an opponent's card effect: you can also select 1 monster in your opponent's Graveyard; Special Summon it to your side of the field in face-up Defense Position.
Dark World's amazing recruiter. This guy can grab ANY DW card from the deck. If you have a hand full of monsters, you can grab the DW Dealings you need to discard them, or grab the DW monster you need to discard, but mostly this card is used to grab the DW Field Spell that we'll look at soon. Also, if it was discarded by your opponent, you can steal a monster from their Graveyard.
Celri, Monk of Dark World
DARK/ 1/Fiend/EffectIf this card is discarded by a card effect, Special Summon this card to your opponent's side of the field in face-up Defense Position. When this card is Special Summoned by the effect of a "Dark World" card, your opponent selects 1 card in their hand and discards it.
A neat little monster that can net you a free DW monster with effects. It can be pretty useful, but I don't see it making a huge impact in the big tournaments.
Gate of the Dark World
Field Spell CardFace-up Fiend-Type monsters gain 300 ATK and DEF. Once per turn: You can banish 1 Fiend-Type monster from your Graveyard; discard 1 Fiend-Type monster, then draw 1 card.
The mighty Field Spell that, along with Grapha and Snow, rockets Dark Worlds to top tier. The most insignificant thing this Field Spell does is raise the ATK of all Fiends by 300. That makes Goldd and Sillva big enough to get over Monarchs, Stardust, and many other cards, and bring Grapha to 3000. The best part about this card is that you can discard 1 card and draw 1 card. That means can basically Special Summon a Goldd/Sillva from your hand and replace it with a new card just by banishing a Fiend from your Graveyard.
Strategy of the Dark
Each player selects 2 cards in their hand and discards them, then draws 2 cards. Your opponent can negate this effect by discarding 1 card.
This card may look nice, but it isn't necessary.. If anything, this may help your opponent by letting them discard Dandylion, Glow-Up Bulb, Spore, Treeborn Frog, or Fishborg Blaster. If your opponent is also playing Dark World, this card helps them more than you.
If the entire deck makes the transition from OCG to TCG, we'll also be getting some nice reprints, some of which we may not see since they were recently reprinted elsewhere.
Dark World Dealings
Allure of Darkness
Deck Devastation Virus
Eradicator Epidemic Virus