Let's say Minor Spoilers here for Star Wars: The Force Awakens, though this is mostly facts and a bit of speculation.
On the official StarWars.com website (disclosure: I am an occasional contributor to that site on a freelance basis), the databank, the official online encyclopaedia of Star Wars, has been getting updates on a regular basis. One such update was spotlighted that includes huge news for Star Wars die-hards.
The Finalizer is the name of the new First Order Star Destroyer, the first thing we see in Star Wars: The Force Awakens. It's the flagship of the First Order fleet, and both General Hux and Kylo Ren can typically be found on it. But it's not just the imposing, twice-the-size-of-an-Imperial-Star-Destroyer look that's significant. The weaponry is the real surprise.
The turbolasers in the Finalizer are powered by a very important artifact in the Star Wars universe: kyber crystals. Traditionally, these special crystals, which are uniquely attuned to the Force, have been used for one purpose: to power lightsabers. Powering giant laser blasters inside a Star Destroyer is a new and nefarious use for them (though there is some speculation that kyber crystals were also used to power the Death Star). What's more, the entry says they were "harvested in the Unknown Regions," revealing a couple more things: this is the first time the dark side has significantly used naturally grown kyber crystals, as the red ones powering their lightsabers are traditionally synthetically made. It also reveals that there are other locations besides Ilum and Lothal that kyber crystals can be found on.
This reveal may seem small to the casual fan, but it's huge in its implications. It opens up the Star Wars galaxy considerably, for one. The bigger deal here, though, is this alternative use for kyber crystals. It implies that the First Order is both much more deeply tied to the Force than we had any indication of before, and that its leader, Supreme Leader Snoke is coming up with completely new ways to use the Force and its artifacts. It'll be interesting to see what we see of this in the future films, and what we see in the books, comics, and other products.