The US TV company only makes these trailers available on mobile devices, so it's tricky to get a high quality version, but we can just about make out a few major points.
We can see a bright sword surrounded by flames, with Melisandre looking into the fire. There's a pair of people on a boat, the symbol of the Faceless Men, a nail going into someone's hand (potentially the crucifixion of the nobles of Meereen), and an owl.
We also see a regal woman, possibly Cersei or Sansa, and someone in a gown running through the woods.
What can we expect from Season 5? (NO spoilers)
Aside from lots and lots of bloodshed, there's a few things we know for certain.
There'll be a lot of new characters, as storylines from the vastly unpopular 'A Feast For Crows' book by George R. R. Martin are folded in.
We can also expect to see the coastal region of Dorne make an appearance, as well as five new Dornish characters (if a leaked casting call can be believed).
Speculation also suggests Tyrion Lannister might be sporting a new look, or may go into hiding after he was forced to flee King's Landing.