The war of thorns, and particularly the battle of Sylvanas and Malfurion, really made me wonder about a WoW fighting game. I think there was even an April Fool's joke about it sometime ago, so I know this isn't a new idea. Since I don't have Photoshop, I loaded up MSPaint and started tinkering to see how something like this would look.
Gotta say, I would love it! Here are a few mock up screenshots of a character select screen I tinkered with. Click to embiggen the screenshots.
Sylvanas (w/Nathanos) vs Malfurion at Teldrassil
Jaina vs Garrosh in Theramore
Brann (and Yogg Saron) vs Tanking Target Dummy in Ulduar
Lorewalker Cho vs The Lich King in The Seat of Knowledge
Wilfred Fizzlebang (and Jaraxxus) vs Rexxar (with Misha, Huffer, and Leokk) in the Trial of the Crusader