Updated: SPOILER / RUMOR!
A rumor that Trek came to Brazil from a very reliable source reveals that the villains of the new film will actually ... ... ... Klingons and we will not have time travel.
Google Translated
Of course take it with a grain of salt and yada yada. But let's look at this for a second. J.J. Abrams said in past interview that he had the Klingons making an appearance in his first movie, but had to cut it. If he had the itch then, than it makes sense that he'd dip back into the well and give us his take on the race.
The Klingons are have gone through a lot of different variations. Originally just bronze colored villains in the original television show, to making the transformation into ridged foreheaded alien looking creatures. The warrior race has also gone from being an allegory on the Russians during the cold war, to being more of a noble group of warriors with like the Japanese Samurai. More importantly they went from villains to becoming allies, but in the current Abram's timeline they would be villains.