This game is coming out on Aug 13. It's a bank heist/RPG/skill tree game that should be awesome. Payday 1 was one of my favorite co-op FPS games, and Payday 2 looks like it'll improve on just about everything. If you haven't played the first one and have friends to co-op with, it's definitely worth picking up during the Steam sale. It's probably the most difficult game I've played in the past decade +, and you actually have to put it on easy for quite a while until your character is good enough to play on normal.
Payday 2, while very much the same as the original in base gameplay, looks to improve on a few flaws from the previous games in that it is a sharper and more polished experience. For instance, gun combat is improved, and the stealth mechanic from the previous game is given a larger emphasis, possibly making it a viable option in each of the 30 heists. Carrying loot is also modified, creating an actual loot bag which adds weight to the carrier, allowing for throwing the loot for a further player to pick up and carry instead. Carrying loot will also tilt the camera due to the added weight.
Cash loot from the game is no longer a substitute for experience points. Instead, it is used as cash for actually making purchases for character and gun upgrades, as well as items that may help on a heist, such as the codes for window shutters to prevent snipers from being able to hit the player while he remains indoors.
New to the game is Crime Net, a brand new mission interface. Not much is known about its functionality, but it has been said that it will unlock certain heists depending on how a previous heist was finished. Whether the heists will be locked again after completing the same heist in a different way remains unknown.