  In the abstract of the paper discussed urlLink here , is the following statement: "DSL development is hard, requiring both domain knowledge and language development expertise. " If MDA, or MDE, or DSLs, or 4GL, or whatever you choose to call it, is to stand any chance of affecting the way software is developed, this statement must be remedied. Obviously, domain knowledge is always going to be necessary, but the second part, language development experience, is something that can be helped. This is the central challenge for MDA, to remedy the first phrase by reducing the need for language development expertise, where that includes the development of compilers, transformations, or the other necessary urlLink glue technology. 
