Bethesda has a history of hinting DLC's and future series games within each release. Fallout 3 had several hints of that nature. But having completed FO4 (170 hours) I'm not really remembering a whole lot so I think I may have missed some stuff.
- there are several references to Alaska
- Jack Cabot talks about going to Arizona after you complete that quest
What else have people seen that may be a DLC or sequel hint?