This seems like a pretty solid overview of the current state of assets representing the value of a USD.
http://cointelegraph.com/news/112637/op-ed-the-biggest-problem-bitcoin-has-are-bitcoins-by-patrick-dugan
I submitted it to reddit
http://www.reddit.com/r/Bitcoin/comments/2hwnep/the_biggest_problem_bitcoin_has_are_bitcoins_on/