The Pokémon TCG: Diamond & Pearl Great Encounters expansion was released on February 13th, 2008. Press release pictures from this set have been added to an Imageboard thread.

Press Release - Latest Card Release Reveals Powerful Diamond & Pearl Pokémon to Seek, Find, and Catch

In Great Encounters, many incredible Pokémon come together to battle in an epic confrontation that will be a triumph for Trainers everywhere. Who will stand victorious? Dialga? Palkia? Or is it Darkrai, a new Legendary Pokémon who rises up from the darkness? With more brand-new Pokémon cards, more Pokémon LV. X, and a titanic clash of some of the most powerful Pokémon ever, Great Encounters is every player’s chance to encounter greatness.

The Pokémon TCG: Diamond & Pearl - Great Encounters expansion will be available in three 60-card theme decks - Eternal Time, Endless Night, and Infinite Space - as well as in booster packs. Theme decks, priced at $11.99, include a unique coin, an updated rulebook, card list, one-player playmat, and damage counters. Each booster pack, priced at $3.79, features 10 randomly inserted game cards.

Meet Darkrai (Great Encounters, 4/106), a pitch-black Pokémon known to lull people to sleep and make them dream during nights of the new moon. Making its grand debut in Diamond & Pearl - Great Encounters, Darkrai is a Darkness-type Basic Pokémon with great attacks and high HP. Its powerful Sleep Hole attack delivers 40 damage to the Defending Pokémon, plus 40 more damage if the Defending Pokémon is Asleep. If the Defending Pokémon is not Asleep, the attack causes it to be Asleep. Either way, your opponent won't be pleased with the outcome. Darkrai's entry into the Pokémon universe will definitely shake things up with a surplus of shadowy new strategies to explore.

Source: http://www.go-pokemon.com/tcg/news/articles/68.html

Diamond & Pearl Great Encounters

Check out the release of Great Encounters to find your new favorite Pokémon!

Darkrai Unleashed!
The moment you’ve been waiting for has arrived! Darkrai makes its first appearance in the Pokémon TCG. Darkrai (4/106) and Darkrai LV.X (104/106) both use powerful attacks that inflict the Asleep Special Condition on the Defending Pokémon. Darkrai LV.X not only has a possible Knock Out option because of that, but its Dark Shadow Poké-Body powers up your basic Darkness Energy cards to be just like Darkness Special Energy cards—10 more damage for each one!

More Cards for LV.X!
Not only does this set feature 4 powerful Pokémon LV.X, it also includes cards that interact with them as well. Milotic (25/106) has the Marvel Scale Poké-Body that protects Milotic from attacks by your opponent’s Pokémon LV.X, while the Trainer card Premier Ball (101/106) always finds a Pokémon LV.X, whether it’s in your deck or in your discard pile. Cresselia LV.X (103/106) adds an extra threat for your opponent to consider—if it Knocks Out a Pokémon with its Moon Skip attack, you draw an extra Prize card.

Get Your Own Energy Boost
There are some Pokémon abilities that just scream to be used in the next deck that you build. Togekiss (11/106) offers a one-shot use of Serene Grace as it comes into play; you can look at the top 10 cards of your deck and then attach the basic Energy cards you find to any of your Pokémon. Maybe you would like a different kind of Energy assist—Sceptile’s (8/106) Wild Growth Poké-Body doubles the effectiveness of Grass Energy attached to your Grass Pokémon. Porygon-Z (6/106) offers a trick for Energy cards instead—discard a basic Energy card for its Conversion Poké-Power, and Porygon-Z changes its type to match... a great tactic for beating the Defending Pokémon’s Weakness.

The Right Tools for the Job
Pokémon Tools appear for the first time in the Diamond & Pearl Series, raising the standard for cards that boost your Pokémon. Amulet Coin (97/106) allows you to draw a card at the end of your turn, if the Pokémon it’s attached to is your Active Pokémon. Maybe you don’t need the extra cards; try out Leftovers (99/106) instead! Leftovers will slowly remove damage counters, giving that Pokémon more time to Knock Out your opponent’s defenders!

Source: https://www.Pokémon.com/us/Pokémon-tcg/majestic-dawn

Eternal Time / Infinite Space / Endless Night Theme Decks

Eternal Time Theme Deck
Tick... Tick... Tick... BOOM! Set the timer to go when you behold the energy inside an Eternal Time theme deck! As Dialga races onto the scene, your opponents will bow before the pressure of its Flash Cannon attack as it forces them to devolve their Pokémon! And lurking in reserve, Primeape is all the backup you could want with its Anger Point Poké-Body: when it has any damage, it powers up with a strength that never ends!

Infinite Space Theme Deck
Prepare to blast through the atmosphere! When you play with an Infinite Space theme deck, the fantastic powers of the cosmos are at your command! Palkia's Transback attack knocks an opponent's forces off the battlefield—making it almost impossible to put together an offensive against you! And, once you've silenced your opposition, Exploud will rip space apart with its Ambient Noise attack that blasts them out into nothingness!

Endless Night Theme Deck
Get ready for the next Pokémon breakthrough—with Darkrai on your team, the opposition will fear the dark! Slipping from the shadows, Darkrai's Sleep Hole attack lulls your enemies to sleep, then hits them with a powerful impact where they lie! Loaded with Darkness, Fire, and Grass Pokémon at the ready, the Endless Night theme deck will make sure you have victory at hand against any opponent!