Stable Value Coins

Once platforms like prism iconomi and melon get up and running I think there will be a large need for stable value coins.

There are a few now but I expect more completion here. Eventually it will be the commercial paper of crypto

1. sbd - our own backed by steem
2. tether - the largest backed by reserves at a central party
3. Bitshares - usd. I don't know much about this. I don't even know it's name but I think they have one that is backed by Bitshares rather than steem.
4. Corion - this is the new one that focuses on variable inflation to hold the price.

I dont know if any of these will last. Corion has not even launched yet! A stable value coin would be nice though.

Are there any more out there?