The main improvements lately have been ones slated for the 0.1.2 milestone, which focuses on basic data management through the web application interface.
The most important improvement is the data upload functionality. We provide a web interface for SHP and TIFF upload and then push the file to GeoServer using its REST configuration API and gsconfig.py. The layer is then exposed via OCG services like any normal GeoServer layer, and so is available for use by OpenLayers and GeoExt applications, for example.
Hat tip to GeoCommons for inspiring the UI for uploading the multiple files needed for Shapefile data.
You can get a taste of some of the other improvements by checking out the Data and Map information pages. In GeoNode, both data sets and maps (compilations of data, with a layer order and styles specified) are first-class content. We want to let users transition seamlessly between working with data and working with maps in order to smooth out the web GIS experience.
The “information pages” (I think we are looking for a better name for these, internally) serve as dashboards to a particular data set or map, and expose the relationships internal to the content. By viewing which maps a data set is a part of, the user can find out about who trusts the data, who finds it authoritative. This is just the first of many ways we plan to let social use of data provide relevant metadata.