I think a reboot will probably be what's next for the Forgotten Realms. This seems to solve few of the complaints that people had with the setting. One complaint was that the Forgotten Realms had too much obscure backstory to get through. How does this solve things? Sure, you might know as much as the grognard about the new setting because so much has changed, but this just adds more ruins for extinct civilizations to figure out the backstory for.
The uber-NPC's that people didn't like (namely Drizzt and Elminster) are still around, plus given the massive changes that have happened in the 3e forgotten realms novels, the PC's still seem to have bit parts. If the novels can take away or change such foundational things as Myth Drannor, the PC's are always going to be second rate heroes.
So I would say that perhaps rebooting would solve these problems. I don't mean changing it back to the original box set (which would only please the very hardcore) but rewrite the setting so that it synthesizes the old and new and thus simplifies the backstory and makes it fresh.
For example, consider this alternate chronology for Myth Drannor. The Drow come out of the Underdark with plans of conquest. They recruit several tribes of savage humanoids of the region. The exiled Siluvanedan Houses who allied with the Dlardrageths join with their ranks, bringing their summoned demons. This army proves an effective engine of destruction, but disintegrates into warring factions over the spoils. The drow army is disbanded and forms small bands of survivors and raiders. The Zhents, looking to cash in on the ruined elven city, summon devils to fight the Demons. They break free because of the Mythal's enchantments, and you now have a Devil vs. Demon turf war.
There, I pretty much put things back to the way they were in the 3rd edition FRCS and removed a whole load of backstory. The story is essentially the same, but reduces overlap between Myth Drannor and the High Forest (which in turn could be an unfallen Illefarn as a point of light to contrast with Myth Drannor's darkness). Plus, I can set it 50-100 years in the past so that Myth Drannor is still fresh for the picking.
This I think would produce a fresher setting than destroying until it is new again, and a lot less forced.