The datasets is a really interesting concept. Maybe SQLite database support? It would need to be some sort of single file database. Then you just need to figure out how to run queries on that data.

We want to do syncing of images, video, and audio. It would be nice to be able to construct a well designed page by dropping assets (text files, images, other media) into a directory in Dropbox and having Droptype automagically arrange those items.