What about MDD.
Marketing makes up shit that either is stupid or cannot be done, then says its easy, and because it promises it to future clients, then creates the framework for development features.
Problem is either these ideas or old or shit, or just cannot be done nicely without a well defined and tried and tested workflow.
Gradual evolution based development, like Firefox and Linux are the only ways to go. Know your features, code for them, then tell marketing to work of a working copy, not a pie in sky shit that makes presales look good.