Via Gameinformer:

After quashing the idea that they would make a return for the sequel, DICE has some good news for fans. Platoons are coming back, and early access applications are open. In order to be considered for the trial group, you need to respond in this thread with your Battlelog/Origin name. If you have a pre-existing platoon, your chances for being selected will be improved.

Am I crazy for not remembering this from Battlefield 3?