I've never really understood the reticence that people have over the many high-level characters in FR. It's not like, in all the world, every adventurer is going to bump into Elminster or Drizzt at some point any more than every character will bump into Mordenkainen or one of the Circle of Eight in Greyhawk. So why does FR hold that stigma where other settings don't?
That being said, the 100 year time difference is going to make things interesting for the likes of Drizzt. Makes me wonder what happened with Catte Brie, Wulfgar and Bruenor. And what level Drizzt will be up to by then. Aslo, what happens to Spellfire now that magic's all topsy turvy... or was Spellfire the prelude to Warlocks?
I'm gonna have to cross my fingers and hope that Elistraee and her woshippers are still around somehow. Though, some form of merger with Selune a-la Sharess and Bast could be cool.
The Spellplague actually interests me more than anything else. One thing I've always liked about FR, Wild and Dead magic zones, and now Spellplague zones. As far as I'm concerned, anything that allows you to mess with players is a good thing.

And, in addition, spellplague zones could give characters interesting twists in background and mechanics.
More than anything else, though, I'm looking forward to the new rules on Fey'ri. I've always wanted to play a Fey'ri character, but races with LA always left a bad taste in my mouth. Now, I might be able to play a Fey'ri Warlock without the hassle.