The new Target Platform story has resulted in a few changes to the Target Definition Editor.
The Environment page remains unchanged. The Overview page has been renamed to Definition page. The page is less confusing now. Earlier it had the workspace target topped with additional directories. But now its just a set of locations which can be any directory, eclipse (or eclipse based product) installation, features or can even be an update site.
Target Definition Editor - Definition Page
The Content page too as gone simpler. It not only shows the constituent plug-ins for the selected locations but also helps in choosing the individual plug-ins out of each location. The plug-ins can be filtered and also be grouped by their location or the file path. As before, the Add Required button adds the required plug-ins for the selected ones. And the good thing is that it searches for the required plug-ins in all the available locations.
Target Definition Editor - Content Page