I am of the personal opinion that a price feed is necessary to oblige parties to make markets at the peg price. As such, I think improving the quality of price feeds is a critical issue that we must address better.
So here's more food for thought- What if anybody were able to submit price feeds and be rewarded for their accuracy per block in doing so?
For example, it might be possible for some delegates to act as arbiters of price feed quality. Most of their delegate pay could be passed through to fund rewards to price feed submitters. The advantage of this is that delegates as a collective group are not required to be experts in price feeds or burdened with that role, but there is a source of reward now available for anybody who can offer this service the best. The arbiter delegates can easily be voted in or out according to how well the do their job of incentivising accurate and timely price feeds.
(Ultimately it would be better for the arbiters to be hired by the community in some other form than delegates, so that all delegates can focus purely on their key role of blockchain integrity.)
Now the pool could be distrubuted based on a transparent, verifiable, hindsight measure of accuracy. For example, arbiters might follow a policy of taking a price history from several official and public sources, combining them in some transparent way, and periodically (e.g. daily) comparing those against all price feeds submitted in that period. The distribution algorithm would take into account the error against the official source on each block. If feed prices are poor, the available reward incentivizes better submitters to join. The incentive can also be varied as necessary by the community by voting in more or fewer arbiter delegates.
I think such a hindsight-measured system could be more robust than alternatives such as prediction markets raised in the past. The problem with rewarding people for how close they are to a median or average price, is that even if some people can provide greater accuracy, they are incentivized to submit feeds that match the average error or lagginess of everybody else. A hindsight reward against official sources avoids this.
Anyway that's just some extra ideas to throw in the mix.
[Edit: an after-thought on this is that rather than using the median price feed for the trading engine, another possibility is we could use a price feed weighted by the accuracy of all past submitters.]