The saag list has a thread discussing “SHA-1 to SHA-n transition”, with all the expected bumps, wrinkles, and sad realities. But entertaining and thoughtful. My favorite comment at the moment is one of Peter Gutmann’s:
It looks like we’re nowhere near admitting that we have a
problem yet if the response to the failure of PKI is PKI-me-harder.
It’s a little like the problem of building a boat in your basement, and then seeing you can’t get it out. Is this a design issue, a deployment issue, or have we fundamentally misunderstood the project? (Once you add local zoning and construction regulations, it’s not long before you wish you’d never started this damn boat.)