Kobold Avenger: The "core" game is set in the world just after the end of events from
Warcraft III, but you get a good grounding in the history leading up to the present time. It's the "Warcraft" RPG, not the "Warcraft III" RPG -- if that's clear.

From what I gather, expansions for
Warcraft III are not taken into account for the core game; as you suggest, though, future releases might cover this material (I honestly do not know such information -- I'm just the editor

).
RedCliff: Thanks for the issue #. Yes, there's the article right there. Good piece, too, by the way!
kilamanjaro: I have no idea if Clifford's article was deemed "official" with regard to any future Warcraft RPG (the article is in the Sept. 2002 issue); it seems more like the usual Silicon Sorcery thing of designing some mechanics based on a computer game. Thus, the two PrC's that Clifford designed do not appear in the first
Warcraft RPG book as they were presented in his
Dragon article; the S&SS team involved different writers.
Impeesa: See my response to Kobold Avenger, above, for the timeline covered by the game. You could certainly run the sort of campaign you want (and it sounds like a fabulous idea!), I think, though the game does focus on the setting after the end of the Third War. You'll likely need the monster book to handle the Burning Legion, however.

With regard to "being done right," as I wrote earlier, the game is the "Dungeons & Dragons Warcraft RPG" -- so you won't see tweaks to the d20 System on the level of
Star Wars or
Spycraft. Certainly, rules are added to express some of the unique and awesome elements of the setting, and the base D&D game is tailored to fit the Warcraft world more accurately (races, core classes, PrC's, feats, spells, skills, equipment, and such). The rules aren't necessarily "bent"; they're more "adjusted" and "expanded" to express the particular atmosphere and feel of the Warcraft setting as distinguished from your classic, basic D&D game. I feel like things were "done right," most definitely. It's just an awesome setting for D&D. Beyond this sort of vague information, I'm not sure how much more I can (legally) say .... My apologies!
Take care,
Mike