Adding active Nests would be a large change, but one I'd like to see added as well. I think for now an easy fix would be to add links to popular rooms on the homepage. It would be static, but a nice placeholder until we were able to make it dynamic.

Yes, that type of change would most likely need a NIP as well as a lot more modifications to Jam. Everyone would need to sign a transaction that they've joined to post an event of a certain kind for listening participation and then another one for speaking participation.