It shouldn't change too much. DLC Generally just adds new items/equipment. It's the patches that change formula's/data tables and screw with everything.
Some of the mods that change follower behaviour might have problems, in particular a certain well talked about vampire may clash if you have her as a follower.
Both of these answers are right. The only thing really affected is 1 follower. Unless your mod is in one of the cells that a new building is erected or a new cave is installed you should be just fine. If one of your mods conflicts you could always just remove it and wait for an updated version that fixes any of the incompatibilities such as cell occupation.