I would point out that Eberron only escaped the timeline movement handed to the Realms because of all the venom FR incurred and the outcry on the Eberron boards.
So why not Eberron? That would have worked far better than the Realms.Yes Dark Sun would have caused too much confusion.
I initially suggested it because I know of many realms fans that may have dealt with what they did not like about 4e if they did not in addition feel the realms were destroyed for the rules set.
So why not Eberron? That would have worked far better than the Realms.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.