The “preview” column in record table view is handy. I noticed the other day that the image avatar also works with videos (at least in Safari, which supports mp4 background-images).
It would be great to support audio too. In the spirit of using Dato as a CMS for anything that requires a strict schema, I’m using it to organise audio samples for an app, and it would be very useful to be able to scroll through them and preview easily.