You can do multiple inheritance of interfaces. While other types of inheritance can work, more often than not, they cause more problems. Think about inheriting multiple Error methods. Which one fires?

>Were it possible for my clients to go for the runtime cost, I would seriously consider servoy (Ken's video wetted the appetite) - to describe another axis from template/generated vs "GUI is a flexible database/hashmap-tree". The servoy approach reminds me a lot of the modula II libs we worked with DOS when foxpro or GenScreenX generated screens. IMHO the visual studio approach to *designers* and the process it at least steers to is the problem, NOT the CLR or the language [and/or the problem is here in front of the screen].
>update: Part of the problem might also be rooted in the single inheritance only appoach of C# and VB combined with the many different approaches MS throws to us. Mixin approaches could ease it.