Having played the Bad Company 2 Beta, I think I can make an assessment on how the game, according to the beta, is played out and changed compared to the first game. I've put in around eight hours into the beta and reached level/rank 15. Correct me on any of the points I make as I may be mistaken.
Let's start with the graphics, from what I see, the graphics are more crisp and brighter compared to the first game and they seemed to remove the "film grain" that was present in the first game. There are more vibrant colours than seen in the first game. I think they may have fixed the screen tearing. I haven't paid enough attention to notice, so unless you are really looking for it, it isn't noticeable if present. There is also particle effects, dust will fly up when walls are destroyed or when a tank shell hits the ground. The sound design is once again top notch, and to truly appreciate it I refuse to play this game with anything less than full surround sound. The sound affects are simply amazing, the gun sounds are different for every gun and the sound effects change pitch depending on where you are. You can listen to the tank shell being loaded from inside the tank for example. I can't adequately describe it, you must listen for yourselves, but I'm sure those who have played will agree with me in this regard.
Gameplay-wise the game seems more balanced compared to its predecessor. DICE have made it so that it takes less bullets to kill someone than from the first game as some of may (painfully) remember. The recoil seems right as there is more to it than the first game. They also added noticeable bullet drop and rocket drop, you may notice than in the first game rockets fired seemed to go in a perfectly straight line as well as bullets from sniper rifles. The beta map is sized perfectly in my opinion, you'll never find yourself sprinting long distances. It also seems that the map is never advantageous to any side. I have never been continually beat playing as attacker or defender. The game mode in the beta is what I presume to be "Rush" which is essentially the "Gold Rush" mode from the first game. In this mode, an attacking team has a limited number of men to destroy two objectives before the map expands and new objectives are set. The defending team have an unlimited number of men to stop this. They changed the spotting system, so that you have to press the select button to mark enemies for a limited time. When team mates kill those marked enemies, you are rewarded with assist points. The specializations are helpful and they don't seem to negatively impact the balance of the game. The unlock system is also changed. Now, in order to unlock items, you must play and earn points as a specific class to unlock items from that class. They also added more torque to vehicles and made driving them much easier. The Humvee moves faster and handles changes in terrain pretty well. A small crater in the ground won't immediately halt the vehicle or send it out of control.
Let's get to some new and returning additions. The UAV drone is a nifty little machine, you control it from the safety of your base in order to scout the enemy locations. It also has the ability to paint targets, allowing for a missile to fall from the sky and hit their target. It seems that this missile is pretty strong, being able to destroy a tank in one shot depending on where it hits, but this alone won't change the tide of the battle. The defibrillator makes its triumphant return, and reviving fallen teammates can be helpful to the team. It is also capable of killing an enemy, the motion is slightly more quicker than the combat knife. The ATV/quad bikes are fast and nimble vehicles that can be used to quickly get to where you need to go. Snipers would find good use, when they use it to quickly get to a sniping position without notice. If you are bolder, you can use it to get into the enemy base before the enemy can react and try to reach the objective. The destruction seems more detailed, you shoot out a hole in a concrete barrier and make a vantage point with it. You can also completely collapse a building if you damage it enough. Stationary ammo crates of the previous game is done away with in favour of a return to teammates dispensing ammo boxes. Now players don't need to run long distances to find an ammo crate. Although, some players seem to ignore my requests for more ammo.
Bad Company 2 is shaping up to be a competent strategic shooter. Players must work together in order to succeed and those who run and gun will find themselves dying (and being revived) numerous times. With three and a half months to release, I am confident that DICE can take this game and make it even better. Now I just hope that they improved the single-player aspects of the game. Feel free to add more to my comments or tell me if I missed out on something. I want an open discussion on what you think of Bad Company 2 so far. If you have any questions, I'll do my best to try and answer them.