Today Electronic Arts revealed that they plan to release a Limited Edition of Battlefield: Bad Company 2. Unlike most Limited Editions, this one won't cost more than the regular edition or come with any collectibles.
What Battlefield: Bad Company 2 Limited Edition does is immediate unlock two weapons and four vehicle upgrades to give you a head-start in multiplayer. Here is the list of instant unlocks available in the Limited Edition:
Four vehicle warfare unlocks
Improved Vehicle Armor – An up-armor package is mounted on all
vehicle types, decreasing the effect of both explosive and penetrating
warheads, significantly improving vehicle survivability.
Supreme Vehicle Firepower – Additional weapon packages are
mounted for the driver of all armored vehicles, greatly expanding the
range of targets the vehicle can successfully engage and destroy.
Vehicle Motion Sensor – Use this electronics warfare package to
locate enemy units in direct proximity to the vehicle.
Tracer Dart Pistol – This magnetic dart attaches to any vehicle
surface, allowing squad members to track, lock on, and fire rockets
onto moving targets even beyond line of sight.
Two classic Battlefield 1943™ weapons
M1A1 Submachine Gun – Reliable but heavy this classic weapon is
a powerful force in the hands of any Battlefield veteran.
M1911 Pistol – Highly customized M1911 are favored for its
dependability and the power of its large .45 caliber round.
The Limited Edition will be available on the same day as the regular BC2: March 2nd in North America and March 5th in Europe. Presumably the LE is packaged with some sort of code that allows you to acquire these unlockables, which would therefore mean you'd need to buy a new copy.