So you want a fourth Warcraft RTS? Join the club. And although Blizzard doesn't seem to plan on making Warcraft IV any time soon, it just got way easier for some enterprising fan to do it themselves.
Yep, Blizzard just announced that Warcraft III models are now live on the remarkably robust StarCraft II map editor — "three thousand new materials" including heroes, character models, structures, and even spell effects — allowing people to create their own Warcraft maps and scenarios to release on the StarCraft II arcade. All this stuff is live on the public test realm right now, with plans to make it public eventually. So go, brave soldier — make us some Warcraft IV. Or maybe the next Dota.