(snip) The sad thing for me will be if the FR campaign book doesn't include multiple adventuring periods. I'd have to rewind the timeline 100+ years to use most new fluff--and I buy campaign settings primarily for the fluff. At least I have some 2e and 3e materials that should still allow me to run the Realms just fine when I feel like using them.
But I'd buy a new campaign setting book if they'd sell me one that let me play earlier in the timeline.
Um, that wouldn't be practical. At all. Even the maps would have to be different. And nothing is stopping anyone from using earlier material or play in an earlier time period: you just use the earlier campaign setting. Anything else is just a waste of limited resources.
Also, as a fan of FR, I'm not particularly looking forward to the 5E version of FR because of R A Salvatore's heavy involvement. That translates to brain-damaged dwarves with speech impediments, superfluous apostrophes, and a lot of crappy NPCs that make Ed's Chosen of Mystra look playable. Having RAS's stamp on earlier iterations of FR wouldn't be good. Even the
Neverwinter Campaign Setting, as good as it is, feels better once RAS's contributions are excised.
(Don't get me wrong: I am grateful to RAS for keeping FR alive as a brand because of his phenomenally popular books, in the same way as I am grateful to George Lucas for creating
Star Wars. It doesn't mean I want either involved with their respective creations, though....)
IMO, the most important thing for WotC to do with the next version of FR is to make sure the world map is actually usable. I grew to like the 4E Realms but the map is inexcusably bad: it has very few details, and those details it has are often at odds with the text, and the "let's smudge baby poo on some paper"-technique used to create it resulted in a map which is functionally useless. I hope they get Mike Schley or someone else who is a competent cartographer to do the next world map, and not just let a baby with dysentery crawl over a blank sheet of paper before randomly slapping down place names as happened with the 4E world map.