While I was looking in the source of Battlelog, I found a game called BFH. I went into the CSS file for BFH and found some images that relate to this game.
To start off, this is the logo:
And the short logo:
Next, we have some footage:
The background is not that surprising:
The following classes will be present: Operator, Mechanic, Enforcer, Professional
A new Blood Money game mode:
Another game mode called Heist:
This is probably the yet to be announced SWAT game, these are the badges for the teams:
These are the awards you can earn:
These are the weapons:
And the weapon accessories:
And their icons:
The game will probably be developed by Visceral as I have found an image of the Visceral logo in the assets, which is not used anywhere:
With a black background that makes:
Update 3: Battlefield Hardline has been confirmed by EA, seeing their official website: http://www.battlefield.com/hardline. It will be unveiled at E3 on June 9th 2014 at 12:00PM PDT.