EA has accidentally left the back door to its Battlefield blog open, giving the public access to image files currently being hosted there. Among them are these three Battlefield 4 screenshots, presumably showing action from the game's campaign.
They're big images, so be sure to click "expand" to see them as nature intended. Well, as natural as a promo screenshot can get, anyway.
The other two are below.
UPDATE - The trailer has gone live early as well.