The knowledge society has been developed and shaped by amazing improvements during the last two decades. On that development and improvement, social sciences such as psychology or anthropology have also had significant impact as much as real sciences like medicine or engineering, in particular, Information Technology or Information and Communications Technology. The new trends and explosion of knowledge due to Internet and Web technologies have radically changed the way we structure business and its main building block, i.e. "knowledge". Though information/knowledge system development efforts have been regarded formerly as mere informal:ion technology activities, now we have been experiencing alternative ways that a business department models, designs and executes the actual business where information technology professionals assist them with the relevant tools and techniques. Hence, all these advancements force us to revisit the classical definition of "knowledge engineering" which was merely "expert system development". This paper points out the needs for this redefinition by reviewing the steps forward in software engineering and how these steps have supported the knowledge engineering so far. Also, authors put forward an improved definition of knowledge engineering, which raises on the pillars of emerging engineering disciplines such as domain, service and business engineering, as well as transdisciplinary approaches. In short, the authors claim the need for the "rebirth" of Knowledge Engineering.