A machine is called a "she" by the true gear heads and people that honestly love working on, flying, driving, riding, and just looking at those machines. You can't tell me that you have never had any form of sentimental connection to anything made of metal. When something does mean more to you than just a pile of steel and aluminum, it's human nature to personify those parts.
Edit: Anyways, super pumped for Mustang. I can't wait to have a true warbird simulator. Even though it has already been said that there will be missions and campaigns, even if there weren't I would enjoy just flying around.