Maintaining a peg is super easy. Any central bank can provide a DPOS system that will work. Then when they print their next $1B worth, they can issue it on a blockchain instead. In fact I expect Central Banks to use a distributed ledger in the near future. This will also make Bitcoin and all other cryptos mostly obsolete.
why would other crypto become obsolete? Surely, it is the corruption resistant protocol & open source code that has the most compelling case for a network people can trust. Central banks are not well regarded and that trend is set to increase exponentially along with hyperinflation.....
Again - if USD, GBP start having features similar to BTC, without the regulation/taxation burden, businesses will start adopting the technology.
You don't have to sell the idea of corruption resistance to anyone in the space. But the average Joe will go with the path of least resistance.
So they will achieve internet of things with a centralized currency. Look at Gold - there is nothing preventing you today from using Gold as a currency. But it is just too much hassle to do so. It's the same with BTC and altcoins.
EDIT: did some digging. Unless you are doing it wrong. Like this guy:
http://gata.org/node/7696