To be honest, I don't think I will pick up COD: Ghosts yet, because what they have shown so far is generic single player game which I loathed so much. I mean, I have never bought a COD game for fancy storylines which is scripted at every round of the corner. There is usually a leader to guide you in COD games who will order you to walk, run, shoot, dive and what not. I don't someone holding my hands and telling me what to do every other second. That's why I prefer multiplayer and never even touch the SP portion of it.
So far, COD devs have only showcases the side I don't care about, while the DICE has showed what I love. So, picking up Battlefield 4 first is no-brainer. Of course, I will be picking up COD: Ghosts too if the multiplayer manages to pique my interest. But for now, I have preordered Battlefield 4.