It's already been revealed that the Kingons will be included in the story for Star Trek Into Darkness. Director J.J. Abrams recently talked to MTV about their role in the film saying,
We shot some stuff that had klingons in it and then we ended up cutting the scene so it's a deleted scene on the dvd but they are back in this one. Their role in this is definitely adversarial and you'll see how that plays out. But you don't have to know about any preexisting stories to watch this film.
He goes on to talk about the character Carol Marcus in the film, who is played by Alice Eve.
Wouldn't [Chris Pine] like that [having Alice Eve as a love interest]. [Kirk] meets [Carol] fairly early on and again- she plays a science officer, she's someone who is part of the adventure and it's an action-adventure movie so once that gets going it's a difficult thing to park the story and say 'lets do a romantic interlude.' But her role is important, she wouldn't be in the movie otherwise.
I'm excited to see Abrams' Kingons up on the big screen, and I can't wait to see how they end up fitting into this epic looking story.
The film stars Chris Pine, Zachary Quinto, Zoe Saldana, Karl Urban, John Cho, Bruce Greenwood, Simon Pegg, Anton Yelchin, Benedict Cumberbatch, Alice Eve, and Peter Weller, and it hits IMAX3D theaters on May 15th then conventional theaters on May 17th.
In the wake of a shocking act of terror from within their own organization, the crew of The Enterprise is called back home to Earth. In defiance of regulations and with a personal score to settle, Captain Kirk leads his crew on a manhunt to capture an unstoppable force of destruction and bring those responsible to justice. As our heroes are propelled into an epic chess game of life and death, love will be challenged, friendships will be torn apart, and sacrifices must be made for the only family Kirk has left: his crew.