This is a good point, but just a standard for the standard create/read/update (replace)/delete operations combined with some baseline guarantees (like approxima

This is a good point, but just a standard for the standard create/read/update (replace)/delete operations combined with some baseline guarantees (like approximately-last-write-wins eventual consistency) would probably cover a whole lot of applications that currently use S3 (which doesn't support appends anyway). Heck, HTTP already provides verbs that would cover this, it would just require a vendor to carve out a subset of HTTP that a standard-compliant server would support, plus standardize an auth/signing mechanism.