I actually had this idea back when I first started at AgileBits and had to really start maintaining ssh keys for work purposes. Prior to that it was mostly just side projects and my own personal stuff.
Maybe we'll have to kick this one in the pants and see what we can do. No promises of course but I'll be passing this along again since I have a personal investment in that idea :)
I'm the technical head for our cloud business so I've got some pretty specific ideas on how to make this more useful from a day to day operational standpoint (multi-tenant infra support has lots of interesting use cases).