Since characters created in the EotE line have Obligation as a component, I wonder what AoR and F&D characters will have similar to that.
From the video of EotE by FFG, it doesn't appear that they will be going the route of each new rulebook being a more powerful version of the game before it (as in the 40k rpg line of rulebooks).
Each new rulebook will have more options available that all characters can build upon from what I interpreted from the video.
It will be interesting to see how you can mix and match characters from each series as a group.
-ashe-