EA has listed all of the current information on the pre-order bonuses for the upcoming "Call of Duty Killer" Battlefield 3. And they've also provided a handy-dandy FAQ for the Open Beta for kicks.
Purchasing the Limited Edition at Origin or any retailer will give you Back to Karkand, a $14.99 expansion pack that does not yet have a release date but is thankfully not already on the disc (for you to unlock with a code). On Day 1, players will also get the Physical Warfare Pack, though everyone will gain access to it at no extra charge at a later date even if they don't pre-order the game.
Select retailers will offer the SPECACT Kit Upgrade, "a set of 8 multiplayer skins, one for each class and side in Battlefield 3", also on Day 1 as a pre-order bonus. Other retailers will highlight the Dog Tag Pack, which just a set of 10 unique dog tags that serve as in-game signatures, or the Avatar Battlefield 3 Gear, which is exactly what it sounds like for your console avatar. An 870S shotgun and beret for Battlefield Play4Free is also up for grabs on Day 1, though it's a little odd that it's for a different game. Which retailers will have which bonuses will be naield down by mid-August.
The Battlefield 3 Open Beta in September 2011 will give 48 hours of early access to Limited Edition pre-order buyers on the PC via Origin or players with a first-hand Medal of Honor: Limited Edition or Metal of Honor: Tier 1 Edition. Details on how the Open Beta will be delivered and when it will take place are still uncertain but will be revealed soon.