Community manager Bashiok said that flying could be added to Warlords of Draenor in patch 6.1, the first major update after the expansion's release. Players would probably have to meet some kind of "prerequisite" to unlock it.
"Maybe it's gold, maybe it's some kind of epic quest, maybe something more straightforward," Bashiok said on the Battle.net forums. "But we're staying open to changing that post-release if it seems like it's working out really well and we want to keep rolling with it."
"I'm digging that there seems to be a pretty reasonable mix of beta experiences here though. Definitely looking forward to feedback when we get to the max-level content too."
Flying mounts were introduced into the game in 2007. Their use is typically restricted in new expansion packs. Generally players have to hit the new level cap and spend some gold to get the right to fly again. Warlords of Draenor would be the first expansion not to give players any opportunity to fly at launch.
Players are divided on this change. On Twitter, Bashiok retweeted two contrasting options that illustrate the debate:
@Bashiok imho it feels really bad to have a feature taken away after 7 years and then get responses like "maybe you get it, maybe don't"— Rutger (@Rutger1112) July 12, 2014
@Bashiok please dont allow flying in 6.1 i dont want the same anti social, empty, safe, trivial, non immerisve world we had in mists again— jay mckeown (@jay_mckeown) July 12, 2014
Flying mounts do have their advantages and disadvantages. On the one hand, they're very convenient for travel. On the other hand, they make some quests a little too easy. You can just glide over a pack of henchmen to kill their boss for a quest. In a way, it disconnects you from the world below, too. It doesn't matter whether you're in a mountain range or a desert or a jungle if you're able to just soar above it all.
Nonetheless, it was hard to imagine them removing flying mounts from the game permanently. They put so much effort into creating that feature. For third expansion Cataclysm, they remade the game's first two continents to allow flight there. Players have spent time, gold, and real-world money in accumulating dozens of flying mounts, too. Maybe the game would be better in some ways without flight but it would be a destructive change, too.
Warlords of Draenor is currently in closed beta. The expansion should launch by the end of 2014.