DLC and mods are two totally different things. DLC is the official content coming straight from the game developers. It's not a 'mod' in the sense of installing a mod from Nexus or something like that. Mods are going to come to consoles a little later this year, and it's likely going to be through a system that's somewhat comparable to how DLC is installed. Mods for consoles aren't going to be available for a while yet, but that's a totally different matter than the DLC.
Mods on consoles are going to be kind of limited. Microsoft and Sony aren't going to allow nvde mods for a game that doesn't have the corresponding rating, they won't allow mods with copyright issues onto their consoles, and so on, but there will still be plenty of them I'm sure.