The versioning is cool in and of itself, but auto-archiving to Glacier after an expiration date is a fantastic feature. The value-add on that is going to be really great for a lot of teams I work with.

What I'd really love to see on S3, though, is the ability to make partial or append-only updates without needing to re-upload the entire bitstream. As of the last time I checked this wasn't directly possible at the API level (it seems like most people store deltas and "reconstruct" the file programmatically when they need to do this).

This would enable an entire class of use cases that's otherwise not easy to do on S3, but which I think would be useful (streaming logs, sensor data, etc.).