"Destiny is built on a strong foundation of co-op and competitive play and it’s a Bungie game. We love competition, we love that part of the gamer.
We’re not talking about that part of Destiny yet, but you should assume that it’s a Bungie game and we love competitive multiplayer, if you love that then you’ll love Destiny, too."
Which pretty much confirms that Destiny will have a multiplayer component. And why not, they are pretty damn good at it!