Trailer For Warcraft: The Beginning

1. The movie was expected to be fair in the story and Blizzard turned down a lot of would-be directors because Blizzard didn't like the direction they were going to take for the movie. That's not to say that Blizzard won't play favorites like they do for the games, where they constantly favor the Horde. (Azshara, Kalimdor is proof of that after Cataclysm. Look at the zone with your head tilted to the left and you'll see the Horde symbol). So if Blizzard has any say, the Horde will win with little cost. Lore wise, there should be heavy losses for both side and the Horde should win but at a great cost. The Alliance may have a victory as well, for a different reason and also at a great cost.
2. With Blizzard dangling the rights like a carrot, I have no doubt they'll ensure that the director follows the agreement to the letter, making the movies almost, if not on par, with the original lore content.
3. Gaming wise, Pandas didn't make their first appearance until Warcraft 3: Reign of Chaos. Lore wise, they may or may not have had a role to play, at least for those that were from the Wandering Isle. Pandaria however I think would be shrouded in mists during this event, so there would be a very small amount of Pandaren presence, if they show up at all.

Either way, I'm definitely interested in seeing how this movie will play out lore-wise.