"If you own a lot of bitcoin and are concerned about price volatility, you might consider putting it in a dollar denominated account on Coinbase"
http://avc.com/2015/01/feature-friday-us-dollar-wallet/
NuBits vs Coinbase’s US dollar wallet, who wins?
I say that Nubit has the advantage of being decentralized and that you hold your keys, but Coinbase is more secure because Nubit’s peg may fall. If Coinbase goes bankrupt you will probably receive your money (I think?).
Edit: The existence of Coinbase’s US dollar account also shows that there is a demand for holding a non-volatile currency and seamlessly use Bitcoin’s distributed network to transport the value. Just like shapeshift.io and NuBits.