Watched it today, and I have to say I didn't think it was going to be as good as it was.
I don't know TOO much about the whole story line of Warcraft, but with regards to how this movie was made I'd say it was pretty accurate in regards to the First War.
There is obviously more that goes on than just that, but it was pretty cool. IMO I just wish there was more of a showcase of how powerful the magic was. It wasn't showcased too much which was good, but it was too little IMO.
EDIT: Also I forgot to mention, I heard people say that it wasn't good, I do agree but on a certain level. There really isn't any explanation for those who haven't exactly played/known about the history of the whole warcraft thing. You HAVE to pretty much know whats going on and what not, so if you don't know any of the lore and what not you really wont get it that much.