I doubt ODST and Reach were [u]primarily[/u] experiments for Destiny; I think it would be fair to say Bungie have always been interested in creating new experiences and expanding the worlds they create. But this is true of most developers. Thinking of BioWare - you can clearly see the influence of previous games like KOTOR and Jade Empire in Mass Effect, or Baldur's Gate in Dragon Age. I'm looking forward to seeing how Bungie will evolve the elements you've mentioned, and how they'll be used in Destiny.