BitUSD or BitApples solves this problem in a decentralized manner.
Sure, it is good for speculators, but not for real investors.
Imagine that around 70% of all transactions in our decentralized bank happens between Bitcoin and Bitshares. That could be perfectly the case because most people will enter with Bitcoins in order to obtain any other currency, or take loans in BitBTC.
It will happen the same that is happening in Wall ST right now. Because around 60% of all transactions in the world are made in dollars, when the dollar goes up and down, it affects secundary currencies that haven't got the strength to trade against anything which is not the dollar. Example: most currencies in South América trade against the dollar for importation/exportation. If the dollar goes down, they go down too.
Now take our situation: because in our market Bitcoin will be predominant, Bitshares will be drawn at the mercy of Bitcoin. And this has huge implications, specially for DACs, which will all of them be in a similar situation as the South American countries in regard to USA.
So I think that Bitshares will only help to make more secure trades to speculators, but will not help very much DACs, at least while the monopoly of Bitcoin continues, or any other show up.
Think about it.