However, a key feature of the Mapper, the functoids, is a great abstraction when you want it, but is obfuscation when you don't want it.
When you hover over a functoid, show the properties.
Simplify getting to the properties, rather than having to go to the Visual Studio properties window.
Allow grouping composition and copy/paste of a group of functoids.
Comments, like the Orchestration Designer Group shape, would be great.
Much clearer handling of loops and repeating constructs would be helpful, perhaps like the reply about two-level (complexType and simpleType) mapping would help.