Tere's also "keep my table headers frozen" functionality that's often requested along sorting, filtering and pagination.
This was a huge point for me when using the old tablesorter script. They had a plugin called StaticRow that would allow you to add the "static" class to a tr tag and it didn't change when sorting. Did you guys implement that too?
But I think you're right that it would be great to have a pairable tool which adds filtering and possibly another which adds client-side pagination.