Planeswalker decks are decks that rely heavily on Planeswalkers, the new card type that first appeared in Lorwyn.
There are various approaches of Planeswalker deck; however, most of them share a few key planeswalkers Ajani Vengeant and Garruk Wildspeaker. Below are 2 decks that illustrate how Planeswalkers deck works.
Erik Ryding and Wilhelm Dubber Pro Tour Berlin
This version of Planeswalker combos by Rings of Brighthearth with any Planeswalker ability or get out many Planeswalkers in the same time to overwhelm the opponent. The deck simply lets your opponent do whatever they want to do as long as Planeswalkers are gaining counters, the deck can win.
Here is another version of a Planeswalker deck
AJ Sacher in Pro Tour Kyoto '09
This version acts like the once famous 5 color control deck, the game win condition is Cruel Ultimatum or Liliana Vess. The rest of the Planeswalkers can chip away at the opponent's life while all the instants and sorceries defend them well. The reason for this deck puts out no creature is that this allows the deck to disable all creature removal automatically without letting the opponents realize there is actually no creatures.