If World of Warcraft is going to end, I would like to see a rather dramatic, yet awesome cliff-hanger.
Perhaps we're battling the armies of Sargeras in the Pantheon, and we're losing badly! Titans are bestowing us with power, but it just isn't enough. Our job is to ensure the survival and escape of as many people, life-forms or whatever as possible, and weaken the army through attacks on their leaders, and other such mechanics.
I'd like to then see the final encounter where we face the avatar of Sargeras, and he kills the Titans, and as the Pantheon is destroyed, we find that he is actually on his way to Azeroth, hence why his mere avatar is at the Pantheon....!