On July 22, 2014, DICE delayed Battlefield Hardline from its original release date of October 22, 2014 to March 27, 2015. The reason for this delay was to obtain feedback through a public beta and implement many changes into the game before official release, and this is exactly what happened. Battlefield Hardline is currently due for release on March 17, 2015. However, the open multiplayer beta was available from February 3rd until February 8th of 2015 (since the original announcement, the end of the beta has been rescheduled for the end of the day on February 9, 2015), and already, EA is talking about changes that have been addressed and ones that will be addressed due to feedback from some of the 6 million players who are taking part in the open beta. Regardless of EA's motives, one possibly to win back fans who were lost after previous games, EA released an extensive list of changes throughout the beta that addressed many concerns brought up frequently by players of the beta on their public blog.
The first changes addressed seemed to stem from the largest complaint about the game: the gameplay is too slow. Combat, driving, and running seems too slow for many players, and as a result, EA has increased player speed by 10%; those carrying a handgun will experience an extra 10% of speed. Vehicle speed has also been increased by 10%. Camera complaints were also addressed. Many players did not like the camera sway, especially while in combat or running, which takes up most of the game while on foot. In the beta, the customization screen is filled with many options, which has most players confused, and it has since been simplified greatly to appeal the large variety of players. The last large change has to do with vehicle durability: players complained that vehicles are too easy to destroy. This has been fixed by adding a single "sweet spot" to vehicles. I can also assume that the up in vehicle speed will help as well. Many other changes were addressed by EA already including the audio of the game, visuals such as the mini map, and even changes in game types. To visit the whole list of changes, players can go to EA's blog here.
Many concerns about the game that have not been addressed relate to the Frostbite engine being run on the game. GameSpot recently posted a video with a representative speaking about how the engine may limit the game, and hoping that this will be changed or improved as a surprise on official release. While this is possible considering the beta doesn't fully represent the final product, I personally do not think any engine changes will take place. My main reason being that Battlefield Hardline is available on both last generation platforms as well as current ones, so expecting a game with a completely modern engine is possible, but not very realistic considering the game releases next month.
Source1, Source2, Source3, Source4, Source5, Source6