Would this be replacing openlayers in the osm plugin? Or writing a new plugin that can use leaflet (and possibly other libraries including OpenLayers 3?) ?

I think the module should be split in two: one part could simply make an inventory of waypoints and generate GIS files (.csv, .kml, etc). Another could render the map based on those files, and that could be made with leaflet. -- anarcat

Enabling leaflet sounds like a great idea. I've been pining for this since I started using the osm plugin! -- kjs