next should be a great writer theming bonus for works from different writers but the same era. that way you would want to use them and trade great works around more to get optimal benefits.I still would hope for a return of the ability to lightbulb great people. If they also brought back Golden Ages (why, oh why were those eliminated from the game in the first place?), you could use, say a GW and a GA to trigger a Golden Age.
Even if they don't being back Golden Ages... why not use the mechanics from Civ V and give Great Writers the ability to be used as culture bombs? In essence turning them into Great Scientists for the Civics-tree.
S.