Basically, EMF is a framework for developing model driven development (MDD) tools.
The tools you will be interested in are in the Model To Text (M2T) section. Using tools like JET you can generate logic-containing business objects, not just simple DTOs, in any language you want. You can generate code from domain-specific languages (DSL) that you define yourself (usually in XML) or from standard modeling languages (UML or Encore).
When you have picked a modeling language, there are ways to build your models using graphical tools (GMF). In addition, EMF has the validation/translation tools you would expect.
Having tried out several of the code generation tools, I can say that it was a worthwhile experiment. However, it requires a significant investment to learn and puts you at risk of depending on one particular tool. If you find yourself in want of a code generation tool, also consider that you may have a language smell or haven't refactored out enough duplication.