It would be great if there were some sort of generic playlist format, such that IFDB could output it as well as Zoom with it’s library, so that other interpreters, including Parchment, could then display the list and download the games. Would make it easier to share recommended games or other sorts of lists. (With IFDB every list could generate a corresponding playlist, meaning polls and recommended items could be easily gathered form the site.)

Is there already a playlist format we could use for this? If not, what info should it provide?

This could be some sort of microformat (in the sense of which would let you refer to a game in HTML and tag it with its IFID in a machine-readable way. Then you could have a web page or feed that could be also be parsed as a playlist.

Although if you rely on the IFID alone, it needs to be in conjunction with a service that lets you get from that to the metadata and the story file URL (as was originally proposed for Babel). If IFDB was involved this service could be an API onto IFDB.