There has been a big debate about this popular topic. It's the first time I see Martin talking and I liked too much, he started saying "I'm sick of this debate", and this is because too many people try to use the metaphor (Engineering, or Architecture) to try to define what is software development, Martin also suggest a new analogy: Lawyers since they try to establish the relationship between a contract and the company activities.
There has been too much participation from the attendees including the author of the book Software Factories (included in the conference bag). Of course we have feel the tension between those who think in software as a manufacturing approach and those that not.
The final conclusion was: "We must try to concentrate our efforts in how to improve our techniques instead of trying to find the better metaphor or analogy"