Blizzard can't deny they once worked on a game called Rock N' Roll Racing. These two new mounts for World of Warcraft remind me of that game and not necessarily Azeroth. But here they are and they both looks awesome.
Their real-life versions are designed by Paul Teutul Jr and his team, and the bike that gets more votes from player will be turned into an in-game mount by Blizzard.
I wouldn't be surprised though if they put both in the game at the end.
Here's what the fully built Alliance bike looks like:
And here's the Horde one. It's massive:
At this rate, we'll see Terran Siege Tanks roaming around Azeroth in the next expansions.
[Azeroth Choppers, via MMO Champion]