I feel too many questions are being closed, voted to close, and people are being pointed toward Project Management inappropriately. PM.SE is still a beta site, and isn't doing stellar in the metrics. I think people are being too hasty, so here are a few points to consider:
- Software project management is a part of software engineering, which is explicitly listed as something that is on topic. Admittedly, there are no single, universally accepted standard definitions of software engineering, but project management topics are explicitly addressed in two knowledge areas of the Software Engineering Body of Knowlege (Software Engineering Management, Software Engineering Process), and the SWEBOK is the closest thing that exists to defining what is and is not a part of software engineering that I'm aware of.
- There's a large body of work built exclusively around managing and controlling software projects. Work by people such as Barry Boehm, Thomas Glib, Steve McConnell, Frederick Brooks, and Watts Humphrey focus on software projects. There are also organizations such as the SEI and CSSE dedicated to software (and systems) engineering. I searched Amazon for works about "mechanical engineering management" and "electrical engineering management" and couldn't find very many resources related specifically to these engineering fields. Of the engineering fields that I looked for, I found specific resources about civil engineering management and systems engineering management (systems engineering being a combination of mechanical, electrical, and/or software systems).
- Tags related to project management are popular here already. Nearly 500 questions are tagged project-management. Nearly 300 are tagged agile. Nearly 200 tagged scrum. Some less popular tags include waterfall with 17 questions, rational-unified-process with 11, extreme-programming with 17, and development-methodologies with 39.
Although there is nothing precluding software project management questions from PM.SE in their FAQ, I don't think it's wise to migrate questions to that site nor close questions that are about software project management until PM.SE is out of beta. If a question is applicable to a software-intensive project, I think it should remain here. If it's a question applicable to a project that involves software (a systems engineering project) but is focused on the software side, it should also remain here. Other questions are debatable, but I see no reason to splinter the software engineering management questions to a site that isn't even open yet.