It might seem odd to be talking about Battlefield 5 before Battlefield 4 has even be released, but a recent interview with DICE's Patrick Bach has him confirm that the fifth entry in the series will include "More features. More extras. More destruction."
The interview with the NYTimes suggests that the game is "due in just a few years", with Bach suggesting that "every new game needs to be the next big thing", hence the focus on new features, extras and destruction.
While it's not an earth-shattering revelation that DICE are planning on releasing a fifth Battlefield game, it's certainly interesting. Considering the studio are about to ship Battlefield 4 on current and next-gen consoles, and they're working hard on a new Star Wars: Battlefront game and a next-gen Mirror's Edge, it seems that there'll be no respite for the team as they push on into the next generation on consoles.
Battlefield 4 is set to launch on current-gen consoles on October 31, with next-gen versions of the game set to follow thereafter.