Matt Ball of Spatial Sustain describes the interoperability and the focus on templates.
"The site allows you to see a map gallery, to share with groups of like-minded map makers, and to make and publish maps online over the Web and to handheld devices. The site has a great deal of functionality that will be enhanced over time...The site is aimed at community development and lowers the barrier to GIS functionality online...The concept of the template approach to map making is one of the primary enhancements of this release, aiming to create stylized themes and map galleries to reduce the frustrations of entry-level users while also expanding the resources of experts."
This announcement follows hard on the heels of another ESRI's announcement, cloud availability.
(C)ustomers have the option to purchase a cloud-based subscription to ArcGIS Server, ESRI's server-based geographic information system (GIS) software. With this option, users can purchase an annual subscription, which bundles a preconfigured ArcGIS Server instance on Amazon's Elastic Compute Cloud (EC2) infrastructure with 12 months of ESRI technical support and maintenance.