It would be cool to hear them do something like Rush did for R40 where they start with the most recent stuff and go backwards chronologically. It pretty much follows the way they already structure the setlists and allows them to do the usual approach of the predictable final 6 songs (NOTB, Hallowed, etc). Only differences are that they would have to make Iron Maiden the very last song of the night and Fear of the Dark would have to go earlier.
Something like:
The Wicker Man
Days of Future Past
El Dorado
These Colours Don't Run
The Book of Souls
Fear of the Dark
Seventh Son of a Seventh Son
Die With Your Boots On
The Number of the Beast
Rime of the Ancient Mariner
Hallowed Be Thy Name
Run to the Hills
-----------------------------
Sanctuary
Killers
Iron Maiden
Something like:
The Wicker Man
Days of Future Past
El Dorado
These Colours Don't Run
The Book of Souls
Fear of the Dark
Seventh Son of a Seventh Son
Die With Your Boots On
The Number of the Beast
Rime of the Ancient Mariner
Hallowed Be Thy Name
Run to the Hills
-----------------------------
Sanctuary
Killers
Iron Maiden