This comes from the ArcGIS Explorer downloads page - ArcGIS Explorer has detected that a newer version (Build 410) of software is now available. From the AGX blog, Among the new features in Build 410 is the revamped ArcGIS Explorer Resource Center. The Resource Center now includes a Contents tab that provides easy access to both maps and layers. See http://blogs.esri.com/Info/blogs/arcgisexplorerblog/Default.aspx
At the heart of this release is the Resource Center where users can locate free stuff, collaborate with others and more... http://resources.esri.com/arcgisexplorer/
New Resource Center
A new ArcGIS Explorer Resource Center has been published, offering direct access to individual ArcGIS Online Layers as well as Maps. The Resource Center also includes a new Share tab. This tab provides access to an ArcGIS Explorer Community Showcase site which allows you to view and share screen captures, maps, layers, results, and tasks.
Get Driving Directions Task
When using the Get Driving Directions task, when you toggle the Regions setting between Europe and the United States, and Canada, the text boxes for From Here and To Here are cleared, making the entry of new locations easier.
Route Source Data Shown
Previous versions indicated that the route source information was available for North America; this has been renamed to United States and Canada to reflect the route source data more accurately.
Import File Now Supports 3D
When importing a text file or CSV file, you can now specify an elevation field in the Import File dialog.
Decimal Seconds Added
Support for decimal seconds in the status bar and the GoTo Location dialog has been added.
Easier Access to Manage Layers
You can access the Manage Layers dialog box by right-clicking any layer. Manage Layers gives you the ability to reorder or remove layers, or clear the layer cache.
Navigation with ArcGIS Explorer has been enhanced in the following ways.
and much more!