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.
A Reboot would more likely fail. Despite people's "bitching" about Elminster and Drizzt, those two characters are critical to the market--Elminster is the soul of the realms, having been it's "narrator" in a lot of the older product and considered the main character of its creator, Drizzt is now a classic fantasy character in the mold of Conan and Elric, thanks to Salvatore's novels. They may be considered "Mary Sueish" (a term I really hate), "Overpowered", etc, but they are successful. They have been reducing other NPCs power and I think that will satisfy some people.
Keep in mind a total reboot would upset not just the gamers but the novel readers, and since both are tied in together, I doubt they'd do anything to upset the novels--remember, Dragonlance ended up becoming a novel-only line at one point. In my opinion, they are likely to turn this campaign setting into a fiction line and cancel the RPG line if push came to shove.
A reboot would only really work if the property was dormant for years or even decades--like BSG or He-Man. Otherwise, memories would be too new. Most people want the familiar, not the new.
Sorry, hardcore FR fans, but you've been fired. The truth is: FR as it stands has been driving people away (due to complexity and bloat) much faster than it has been attracting new players. Pretty much the only FR fans left are the hardcore fans. Left as it is, interest in FR will just dwindle away.
Do you have sales figures or the information on whether or not sales have dipped? Could it be that the supplements were re-written to new formats people didn't like? Considering how popular the novels are, I don't think this is the case. I think more or less they are trying to make the changes serve their purpose while making it as palatable as possible. I'm sick of people dismissing hard-core fans of anything by implying they are losers or nutjobs. If it wasn't for their passion, FR would die.
I have not been a huge FR fan. As such, the 4e changes to the Realms presented the opportunity to let me reconsider the setting. I like what I've read of the changes in the Realms circa 4e but a number of the changes seem to affect only out of the way places while leaving the "core" Realms (Sword Coast, Dales, Cormyr) largely intact. Thus, it looks like the "core" stays pretty much the same but that the changes to the outer ring of areas give the core areas something new to deal with on their periphery. This is, I think, probably a "safe" strategy but hardly an inspiring one.
Well, the goal was not to complete reboot or change FR, but to bring it in line with the 4th Edition and make it feel fresh for that game.
The suggestions I see people making sort of boggle me. It would be like rewriting Peanuts to make Charlie Brown a cool suave winner and make snoopy a "real dog" without thought balloons. It would be like making Spider-Man a female super-villain.
If you're not a fan of what exists, why would you waste time wanting to play a setting that is completely different yet uses the same name/trademark?
At it's core, Forgotten Realms has a style and certain expectations. Of course they are going to keep the fans interested--if they wanted something completely new they'd just create a new setting! We should expect to see elements like Cormyr and Waterdeep and Myth Drannor, Elminster and Drizzt, Balder's Gate and Neverwinter. We can also expect new things to be put down, new rules of magic to fit the classes, new empires and states for the new races, etc. It's pretty much a compromise.
I'm on board because I don't see a lot of major disrespect, Ed Greenwood is still involved, etc. It looks like they've done the best compromise they could.