Cryptic has published information on the STO preorder exclusives:

Pre-Order Exclusives | Star Trek Online Official Site

Unless otherwise specified, items are available to every character in a player’s account and are mostly used during a character’s early development. None of these items are trade-able.

NX Prefix
This renowned ship registration prefix designates a special prototype vessel. Players can attach this prefix to the title of any of their ships.

Targ/Tribble
A Targ is a cosmetic pet for Klingon characters only that a player can summon and dismiss at will. The Tribble when summoned increases a Federation character’s healing rate, though it cannot be summoned during combat. A character will take out his Tribble and pet it.

Borg Bridge Officer
Each character created receives a reclaimed Borg Bridge Officer to assist him in space and on the ground. The Borg Bridge Officer possesses unique abilities not otherwise available to players. Bridge Officers can serve with the players for the entire game experience. These special Officers are not customizable.

Constitution Class Ship
Shortly after the tutorial, a player assumes command of a ship. A player can choose either a standard Miranda class or this exclusive, the Constitution class ship. Players fly around in a non-customizable replica of the TOS ship beloved for decades. Players control this ship for roughly 20 hours before being promoted into the next class of ship.

Skill Points
Each character created receives an additional 500 skill points at the beginning of gameplay. That’s a 38 percent increase over what players normally receive through the tutorial.

Joined Trill
At character creation, a player can select Trill as a race. This unlocks special exclusive traits that enhance the character’s abilities. Note that the special abilities are the only exclusive aspect; players are still able to create Trills in the game. However, they will lack the Trill abilities.

DS9 Costumes
Players can clothe their Federation characters in the uniforms made famous in the Star Trek: Deep Space Nine TV series. Players can freely change the colors of the uniform.

TOS Costumes
Players can clothe their Federation characters in the uniforms made famous by William Shatner and Leonard Nimoy in the classic Star Trek: The Original Series. Players can freely change the colors of the uniform. Also note: The TOS costumes do include mini-skirts!

Neodymium Deflector Dish
This ship item is goes into a ship’s deflector dish slot. The Neodymium Dish grants a bonus to Auxiliary power, boosting maneuverability and increasing the effectiveness of all of your ship's Science abilities.

Chromodynamic Armor
This ground item goes into a character’s body armor slot. Based on technology brought back from the Delta Quadrant by U.S.S. Voyager, this personal body armor improves the damage and critical hits of a player’s ground energy weapons.

Radiometric Converting Shields
This starship item is slotted into a ship’s shield slot. This starship shield system absorbs theta radiation from incoming attacks and sends the energy directly to your EPS conduits to increase your ships power levels.

Multi-spatial Personal Shield
This ground item slots into a character’s shield slot. This advanced personal shield system is based on Borg technology and constantly regenerates itself and even a character’s health.

TR-116
A player equips this phaser rifle into one of his two ground weapon slots. The TR-116 is rare projectile weapon is used in dampening fields and other challenging environments, it is also modified with a micro-transporter which beams the fired projectiles to targets at close range so that a user can fire without a direct line of site.

Red Matter Capacitor
A unique item slotted into a ship device slot that charges up and delivers extra energy to all of your ship’s equipment for a short time. The Capacitor has a long recharge.

Automated Defense Battery
This ship item slots into the Tactical Console slot. Tactical Module that grants the ship a passive 360 arc attack power with a short range.

KKKHHHHAAAANNN Emote
Players will be able to do the famous Kirk Khan yell from Star Trek II: The Wrath of Khan.

Bloodwine Toast Emote
This gesture is known throughout the galaxy as a hallmark of Klingon society.