My idea of a free DLC would be a Pork-alike rocket parts overhaul. Now if people like the lifesaver and the barrel, they can keep it. In my opinion, pork-alike, pork-alike, PORK-ALIKE.
Yeah, they would have to be from @SQUAD itself, not from other modders. Most likely, the DLCs will be for console releases, since they only have DLCs, not being able to edit the GameData folder on their Xbox One. It's unlikely we PCers would ever see a paid DLC for the game.
Yeah, and consoles should be able to handle more mods faster because instead of things being downloaded and taking up space, it makes room for the game when you eject your other game and put in KSP. Of course, @SQUAD would have to get the modders permission first. The ones who already work at @SQUAD are guaranteed to say yes, and most other modders would jump at the opportunity to make their mod multi-platformal!
Edit: I've mentioned @SQUAD three...no,wait...four times in this post. NOTICE ME! lol