Deploying a new application is, due to the nature of the
Internet and the end to end principle, fairly easy. Upgrading
one has proven to be much harder (e.g., MIME and the SMTP
extensions offered a lot to users, but I'd guess we are still
well under 90% penentration of competent and conforming
implementations nearly seven years out). And changing
infrastructure --and the DNS and its protocols is certainly
infrastructure-- is much worse, since both the servers/resolvers
and the applications need to be upgraded.
This observation is the key to discussions like these.
- A new application can widely deploy in 6months to 1 year, rather easily.
- Upgrading a massively installed base is a factor of 10 worse. For lucky upgrades, there is incremental utility for each upgraded application. MIME was an excellent example.
- Upgrading an infrastructure is another multiple of 2 to 4. There is no incremental utility. Utility occurs only after deployment is wide-spread. That actually causes a disincentive. SMTP DSN is perhaps an example.
