With the upcoming addition of the Romulan faction, and their use of singularity warp cores, it appears that Cryptic has decided that it’s a good time to introduce Warp cores as a new ship item. From the Tribble release notes :

http://sto-forum.perfectworld.com/showthread.php?p=8988361#post8988361 …

Warp Cores:

• All ships in the game now have a Warp Core slot.
  • All KDF and Starfleet vessels use Matter/Antimatter Warp Cores.
• The way in which Warp Speed in Sector Space is calculated has been updated.
  • It is now based off the level of your ship’s Warp Core, instead of off your captain level.
  • Additionally, the scale of Warp Speed throughout the game has been recalculated to allow players to go faster in Sector Space but maintain Warp 10 as the fastest displayed non-Transwarp speed.
    • A speed that previously displayed as Warp 7 now displays as Warp 5, but is actually the same speed.
    • This means captains moving at Warp 10 will now reach their destinations more quickly than they could before.
• Warp Cores of every rarity now drop from space combat throughout the game. As your Warp Core increases in rarity, it gains additional pools of possible enhancements to add to your ship.
  • All Matter/Anti-Matter Warp Cores increase the Maximum power of either Shields, Engines, or Auxiliary by 5.
  • Uncommon quality Warp Cores add a bonus of 15 to an Engineering-related skill.
    • There are six possible enhancements you can receive on a green warp core:
      • Driver Coil
      • Starship Batteries
      • Warp Core Efficiency
      • Subsystem Repair
      • Electro-Plasma Systems
      • Starship Engine Performance
  • Rare quality Warp Cores add a synergy bonus between one power system and another.
    • For example, one possible Rare enhancement will give you bonus Weapon power equal to a percentage of your current Engine power.
    • There are twelve possible enhancements at the Rare level.
  • Very Rare quality Warp Cores add a new power to your useable powers, a Capacitor.
    • Capacitor powers function as reusable batteries that don’t occupy a device slot, but have a longer cooldown and lower magnitude of effect than a standard battery.
    • There are four enhancements at the Very Rare level, one for each battery type.
• Mk XI and XII Warp Cores of all qualities gain one additional travel-related enhancement that increases the usefulness of your Slipstream or Transwarp abilities.
• A selection of Warp Cores can be purchased from Energy Credit vendors in most social hubs, as well as through the Dilithium store.
• All told, the Warp Core slot is designed to add a lot of choice in how you configure your ship’s power settings and Engineering abilities.
  • There are tens of thousands of possible cores out there to find and use, and tons of new builds to make with them, so good luck and happy hunting!