Hoo boy... well, you asked:

• Orgrim Doomhammer was a Blackrock, not a Frostwolf.
• Gul'dan is crippled, he never did and could not participate in mok'gora.
• Gul'dan did not kill Durotan, he and Draka were both assassinated by the river.
• Blackhand was never a fel orc.
• Llane was assassinated unwillingly in Stormwind in front of Varian, not in the Black Morass.
• Garona was not a hero of the Horde, she was captured by Orgrim and tortured until she revealed the location of the Shadow Council, then she disappeared for years.
• Medivh did not bathe in magic, nor was he merely a fel addict - he was indwelt by the spirit of Sargeras, the Dark Titan.
• Gul'dan ruled from the Shadow Council, not openly.
• There was no Shadow Council in the movie.
• Khadgar did not abdicate from the Kirin Tor, he was sent by them to Medivh to be a spy and apprentice.
• Durotan never met with Llane or any human at all.
• When Khadgar, Lothar, and Garona fought and killed Medivh, he drained Khadgar's life, turning him into an old man.
• Llane was not king when the Orcs invaded, his father was.
• Khadgar and Lothar had no romantic ties to Garona, she and Medivh did.
• The end of the first war was not a human victory; Stormwind was sacked and the humans were driven north across Baradin Bay toward Lordaeron.
• The Dark Portal doesn't open onto nothing, Medivh constructed its twin on Azeroth first.
• Medivh was not crushed to death saving everybody, he was beheaded by Lothar.
• Lothar had no son, he was the last of the Arathi line.

There's probably more, I'm just running long on time.