I would like to see some rewards for playing/beating previous Bioware games.
Indeed it would be fantastic to have Bioware Legacy items for cd keys we could paste in (since not all our BioWare games are on Origin), or even as easter eggs to find across the world or as a holidays DLC pack, especially for the Legacy titles. And... it actually might be a fun thing to do for the guys and gals who actually worked on those earlier projects! Blast from the past! 
Fun things like...
An asian weapon for Jade Empire
Revan's mask for KOTOR
Aribeth's armor for Neverwinter Nights (or any number of models and references? please?)
Blood Dragon for DAO
Vigilence for Awakening
A class apropriate mantle of the champion set for DA2
A Jedi or Sith robe for SWTOR, according to the decisions made by the player so far (surely there is some form of pragon/renegade scale in DAI?)
A staff that casts "Singularity" for ME1
A Miranda/Jacob medium armor in Inquisition colours and logo for ME2
A Krogan Battlemaster hammer for ME3
One can dream, right?