UPDATE: Bungie has responded on the forums, in essence saying, "Yes, that stuff is true but we have nothing more to say."
We noticed that you noticed that we already have plans for upcoming content packs in Destiny.
We do! They have activity names (which may or may not change) and we have a really good idea what they're going to contain. They even have placeholder nodes in the Director, as you've already discovered.
But neither of the Expansion Packs we've announced are finished.
People at Bungie are hard at work to complete content for our first post launch pack, "The Dark Below," as I type these words. It will be finished soon. It releases in December. Soon, we'll detail it out for you so you can see exactly what we've been working on.
A Destiny player has uncovered what may be coming in the future for the game. The discovery was made due to a bug in the latest Destiny update that allowed Kinsey_92 to ferret out hints about forthcoming events, raids and more.
According to Polygon:
A video uploaded by the gamer introduces the bug which appeared to affect the map screen following a patch to Destiny over the weekend. Moving the cursor over certain planets resulted in the message "requirements not met" and "expansions required," both of which appeared during Destiny's alpha and beta periods when locked out of the game's primary mission.
The bug seemingly leaked a number of incoming story missions, strikes, raids and Crucible content under the name of two planned expansions: The Dark Below and House of Wolves.