As promised here is the PC Blog on the Beta & a few other things, yes some people, places, and things may have leaked a little something, but we are here to clarify everything and make it all official since we can now commit to the listed dates! :-)

BETA Details:

-Beta Begins/Ends: Jan 28th/Feb 25th
-Map Name: Port Valdez
-Players: 32
-Game Mode: Rush
-Environment: Snow
-Theme: Vehicle and Infantry

Back Story:

The battle for Port Valdez is fought alongside the waterline towards a great oil industrial landscape in the Alaskan mountains. Using basically everything they've got the Russian forces are launching an airborne assault to knock out the oil industries in the area. In their arsenal there are Main Battle Tanks as well as fast-moving Quad Bikes and mobile armored AA. It's a vehicle focused battle, but with plenty of infantry combat.

How to Download: Check back to the Battlefield Bad Company 2 Beta Page closer to beta launch date for download instructions.

How To Get Access: Reserve Battlefield Bad Company 2 is the most sure fire way and right now we are still finalizing which Retailers & e-Tailers will participate (it's up to them). If you're eager to ensure you get in confirmed distributors to Pre-Order consumers are the EA Store and at GameStop.com. We'll have another Blog to update new retailers & e-Tailers that have teamed up with us as well as alternate channels to obtain a Closed Beta Key.

Misc. Details

Steam Beta: Yes there was a leaked image of a Package file we propped on Steam. People with illegal accounts can see games in this environment, but this is not a Beta in the term of Public Test Beta, but a real development Beta installer client for the Steam version of the full game. We are however working with Steam to have the Public PC Beta available on Steam, but can't confirm this quite yet so cross your fingers Steam users. :-)

Anti Cheat: We're going with PunkBuster supporting the same options BF2 and BF2142 had to run unranked without PunkBuster.

Mod Tools: There will not be mod tools for BFBC2. However a majority of the the games logic is controlled by the server and there will be Serverside control options for the dedicated servers.

Public Server Files: We will not distribute these publicly. There are many factors for why we have decided this with the biggest factor being security & integrity of our game & Dedicated Servers.

Source