Since I have no faith in the US dollar, I originally was not interested in this. Why stabilize something to the dollar when the dollar is so inflationary? I buy something today, a month or so later it will cost more, and each few months later, the cost is higher again. I compared things I regularly buy and a year or two earlier they were significantly lower in price. So the DAI is stable because it is matched to the dollar? No. It becomes just as unstable as the dollar. Perhaps the DAI will not be going up and then down and back again, but basically it means it will continue to go downward in value for goods.
That being said, the concept is good for the stability for managing a retail business and the security, infrastructure, and principles behind it seem very sound. Sure beats the banks we have today and avoids the centralization and introduces accountability.
One big question: If the dollar crashes, what will the DAI then be "against". All the various kinds of collateral is excellent, but the whole theme is to be tied to the dollar. If it crashes, why would we even want it? Needs a backup plan for that situation.
DAI is not something that is meant to be held as an investment to earn money in my opinion. It is a place to park money when you need stability short term. The backers then take your crypto currency risk. If ETH goes up you lose, if ETH goes down you gain. Vice versa for backers. Until something can replace USD as the world currency it will continue to be the preferred option for pegging to. Currently crypto can easily swing 20%+ in a day. As of yet we are not even remotely close to seeing that happen to USD. Once DAI is on a major exchange it will be a very usefully tool to hold between trades just like people love to use USDT even though they should have very little reason to trust Tethers value.
Really the ideal peg would be to the average cost of a unit of labour. In the end that is all currency is, a way to trade one's labour for goods.