I'm pretty confident that you'll at least be able to fly the ships yourself, and if you can fly them, you'll probably be able to fight them like in Reach :P They've already confirmed in interviews and the Mail Bag that you can buy different ships (plus, different ships in the ViDoc) and my reasoning is this: Since they give you the ability to even [i]have[/i] a ship, and they let you buy [i]other[/i] ships, and they give you the options to make your ship even [i]cooler,[/i] Bungie [i]KNOWS[/i] you're not going to want to just admire it in a "garage" or use it simply as fast travel. You're gonna want to fly that sucker, and you're gonna want to have space dogfights with that sucker. I just don't see any other possibility :P