Based on what we know now. I think Bungie can easily rectify the "story is non-existent" in DLC; however, that doesn't fix the retail launch title, just makes up for its lack of a narrative.

The lack of non-fireteam chat is perplexing, especially in a game that is touted as so social.

I have mentioned this before, but I hope a high-level social space becomes available with high-level content.

Te ability to trade would be great. Some sort of crafting system would be cool, too. Although, I think that lands outside the scope of Destiny. I don't expect that to ever be implemented.