AutoCAD Architecture 2010 aka Botta.
AutoCAD 2010 news that are also relevant for Autodesk Architectural 2010.
The DWG file format is new and not compatible with older versions.
UI Contextual Tabs
New, streamlined user interface that offers an optimized organization of tools for quicker access to tools and commands.
Wall endcap editing has been improved by joining Trim and Extend commands
New wall cleanup editing capabilities help improve wall drafting
Common AutoCAD commands such has Trim and Extend have been joined by
A new Space Separator tool has been added, allowing users to
A new flip text position grip for AEC Dimensions has been added, giving
More accurately design and annotate drawings with an improved stairs
Part files and assemblies from Autodesk® Inventor® software can be
When exporting designs via industry foundation class (IFC), relevant
If you have .NET code that worked with older versions you need to recompile.
http://blog.jtbworld.com for more tips & tricks.