ArcGIS 10.1 will make it simpler to put mapping and geospatial analytics into the hands of more people without requiring that they be GIS experts. One of the most important aspects of this release is that ArcGIS users will be able to deliver any GIS resource, such as maps, imagery, geodatabases, and tools, as a web service.
ArcGIS will support more imagery sources, as well as lidar and radar. Also, A great adding to ArcGIS at 10.1 will be ArcGIS Runtime, which allow developers to create and to deploy focused, stand-alone GIS applications for desktop users.
On the top of these improvements, Esri focused on providing core GIS tools to make it easier for users to create quality maps. Dynamic legends to contextual generalization, the ability to track edits, parcel editing tools, analysis tools, and a whole lot more tools.
Lastly Esri bridges the gap between GIS Analyst and programmers as Python will become central to ArcGIs with ArcGis 10.1.