When you put your brand new copy of Battlefield: Bad Company 2 in your system for the first time, you'll be treated like a VIP.  That is, you will receive a "VIP" code to enter into your EA account that is tied to your Gamertag/PSN name.  This code will allow you to download DLC for the game, and will include some free goodies on day 1.  The idea is very much like Mass Effect 2's Cerberus Network.  If you liked the way that worked, and didn't have any trouble linking the accounts, then this should be good news for you.

Senior Producer on the game, Patrick Bach, stated that the free day 1 DLC will be a set of new multiplayer maps.

Personally, I think the decision by EA to include this system in more of their games is a smart one.  It's mainly to combat used sales, and this is a great way of achieving that goal.  EA charged $15 for access to Mass Effect 2's Cerberus Network if you didn't buy it new, which would make many people think twice about doing so.  If you get the game for say $20 used sometime after the game comes out, then putting $15 in the pocket of the company that made the game (as opposed to nothing from the actual used sale) isn't a bad deal.  I know a lot of people may be ticked if they plan on buying this game used, (or other EA games that may use this system) but I'd much rather give my money to the creator, not Gamestop, etc.

Tip - Amazon is currently offering a $20 video game credit with the pre-order of the game.  If you plan on buying it when it releases, I'd recommend jumping on that deal while you can.

Battlefield: Bad Company 2 rolls out March 2, 2010.

Source: MTV Multiplayer