Mapbox.js is moving forward to fit our powerful new drawing tools on Mapbox:
today’s version 1.6.0 introduces support for L.mapbox.featureLayer, a successor
to L.mapbox.markerLayer that supports lines and polygons as well as simple markers.
With the introduction of styled line and polygon features we also extended the simplestyle specification, an open standard for styling GeoJSON data. This means that the features that you style in the Mapbox interface will display the same in Mapbox.js, and your own simplestyle-formatted data will be styled.
We’re making developer documentation work better: Mapbox.js is a Leaflet plugin, but in the past the documentation for the two projects was in different places and hard to cross-reference. Now, you can browse both Mapbox.js and Leaflet documentation in the same place, and you have the choice to view it as short pages or ona single, huge comprehensive page.