Product Management IS at the core
My name is Steven Haines and I'm the author of several books about Product Management, including The Product Manager's Desk Reference, and Managing Product Management.
First of all, I'm really happy that John mentions the fact that Product Management is a function in a company, and that product managers contribute greatly to innovative products. Some great examples were also cited.
My comment is about Product Management in tech companies. In my research, I've seen that PM has been drawn into the vortex of product development. Yet,what's really needed is the business perspective. A product manager, as John points out, is not a CEO, yet executives want product managers think like a CEO (or a business owner). Product managers must integrate the work of others in order to get the business of the product done.
However, there's one thing that was missed in this article, and that's vision and strategy. Strong product leaders have the wherewithal to envision a future, identify key strategic initiatives, secure funding, harness cross-functional resources, and at the end of the day, deliver a profit.