Our good friend Kevin Kelly (who writes for Joystiq) has apparently turned traitor -- over at the Spout blog, he's written up four reasons why they shouldn't bother making a Warcraft movie at all. His arguments go from shaky to solid -- he first claims that movies made from videogames just don't work anyway, In response, I'd submit to you Doom, and -- oh wait. Never mind. His second reason is that they just wouldn't make enough money, even if every Warcraft player bought a ticket, but I don't know if I'd worry about that: Transformers made money, and that movie was a high-budget pile of junk.
His last two points are probably more solid, though -- he says that unlike Lord of the Rings, which the Warcraft movie is often compared to, most people (even players of the games who skip cutscenes) would walk in having no idea what the story was about, which means the story would have to be dumbed down or just be a confusing mess. And finally, we can't really argue with the last point: since that first piece of concept art, we haven't heard a peep out of Legendary or Blizzard about what's happening, so maybe the flick's not getting made anyway.
And by the end of the piece, we've got to agree with Kevin: even if a big-budget worldwide movie release didn't get made, we'd much rather have a high-quality DVD of Blizzard's cinematics anyway (or maybe even a feature-length put together by the same department -- they do awesome work). The odds are against a live-action Warcraft movie already, it seems -- maybe it would be a better idea for Blizzard to just release something themselves.