First off, I directed the 3.5 version of the campaign. I'm not involved in the transition to 4e, so some of this might change.
Now, there's 'epic' in the narrative sense, as in, you're leading armies against armies, and defending a city against a living tempest, and fighting a 90-ft. colossus. Or there's 'epic' in the mechanical sense, as in, higher than X level.
True, a lot of the enemies are humans, but at higher levels, they're hardly mundane individuals, and the situations where you encounter them are not simple dungeon crawls. You're exploring the nightmarish dreamscape of a psionic dragon, or chasing a shadowdancer through a haunted forest to retrieve an artifact he's stolen, or assaulting the command center of an eldritch doomsday device. I think it's appropriately epic, and there are more monsters than in, say, Lord of the Rings.
I'm pretty sure the 4e version will have more interesting monsters, and rely less on soldiers and mages and such. I mean, in 4e, there are more high level monsters that are actually open content compared to 3e.
As for fitting it into the Realms, I think it works with a little wiggling. I ran a brief playtest set in and around 'near future' Thay. Instead of having the Ragesians be opposed to all spellcasters, I had the Thayans trying to capture disloyal spellcasters. Aglarond got a bit more aggressive because they have to defend themselves against the Thayans, who recently allied with . . . I don't recall which nearby nation, but someone who could field a large military.
I don't know how FR changed in 4e, but I think you can do it. Szass Tam takes the place of Emperor Coaltongue, and has been stewarding a new artifact created during the spellplague - the Torch of the Burning Sky, which can teleport whole armies at once. With its power, Thay has been expanding its influence. Say, perhaps they forced the Hordelands to ally with them, along with a few groups from Rashemen, and they're putting pressure on other nearby nations.
Szass Tam's death under mysterious circumstances leaves a power vacuum among the Zulkirs, with Lallara (or whoever the current the abjuration zulkir is) taking the place of Leska. She convinces most of the nation that traitors destroyed Szass Tam, and sets out inquisitors to capture disloyal mages. Somehow the combination of Tam's destruction and the Torch's power causes all teleportation to become hazardous in the region, so Thay sends out its armies to try to retrieve the Torch.
Aglarond takes the place of Shahalesti, as both are nations with strong magical powers. In the 4e time period, I believe the Simbul is out, so Shaaladel could just be a general who is leading the fight against Thay. Sure, in the campaign saga they're all supposed to be elves, but in 4e that is ridiculously easy to change. Ditto the half-orcs working for Thay. Just make them horde-folk.
Rotate the presumed map of WotBS 180 degrees, and have the resistance be in the north instead of the south. Dassen becomes Thesk, Sindaire becomes Rashemen, and Ostalin becomes . . . well, that's about the limit of my knowledge of that region. But I'm sure somebody's there.
I hope you find a way to use it. Let me know if you have any question.
) It certainly came across to me as that was the way it was intended to be run.
