I'm one of those that loves FR as a campaign setting, I've always felt it was very diverse in what it offers with the terrain, history, factions, etc. The last campaign I DM'd to 30th in 4E was in FR the whole time and my players seemed to like it as well.
I'm currently DMing FR for the first time, and there certainly seems a lot of potential there. I'm finding the 4e FR player book & campaign guide to be great resources in play, my players love the Loudwater stuff, especially that Lady Moonfire!![]()
I love closure, but I don't actually plan D&D games out to 20 (or 30, these days). Rather, I enjoy running a game for about a five-level arc or so, getting to a major climactic point, and then seeing where the group's energy level is. If they want to go on for another five-or-so arc, usually it's because enough has happened that the next arc should write itself.
"Not long for this world" is really a matter of personal taste, I guess. I can see lots of characters hitting extremely satisfying milestones in about five levels of play. When I have to be taking level 20 into account as I'm setting the stage for a level 1 adventure, that starts getting into thousand-yard-stare territory.
I don't like plotting out long campaign arcs, or anything above a couple sessions really. But I'm coming to like it that the Forgotten Realms CG has a bunch of suitable campaign-ending villains I can use if we wanted to go to level 30 say.