User stories for things we might want flocker to be able to do

Story: https://github.com/ClusterHQ/flocker/issues/236
This is the start of a story, but it's missing lots and lots of details, some of which would presumably be exciting to users. As it is it's vague to the point of meaninglessness.

I can imagine the following build up:

1. Flocker detects the image has changed and starts/stops that container.
2. Flocker detects new image failed to start, falls back to old image.
3. An automatic smoke test can be provided; if it fails revert to old image.
4. Introduce volume management: pre-upgrade data is preserved, if upgrade fails revert to old image and old data.

There's questions about whether we revert to full old configuration, rather than just single container? This starts getting into what the level of upgrades is...

I'm not sure what level of detail you have here, and what the specific audience is. If this is an attempt to interest potential users maybe we should expand on data-specific things that only we can do.