The Release Manager is the Product Owner

What's a release manager? A marketer. A public relations fellow. Someone that cares both about the customer AND the product development team but in no specific order. This person is the best possible person you could have on your team or company. They can turn a bad project into a good one and a good one into a bad one. If you have someone acting in a release manager capacity that is either A) all about the requirements or B) all about giving the customer everything they want regardless of cost, you're in trouble.

Train people in this role how to help you out, provide air-cover, and also how to serve the customer. If you are the guy/gal responsible for delivering the product find someone who complements you very well and understands how to communicate, deflect, and the like. I'm not yet sure if the Release Manager needs to be technical in a software project but I believe the answer is definitely yes, since if they aren't they can't deflect and backlog as necessary, that would end up falling to you.

Business Intelligence As Feeding the Hungry

The business is hungry for information about their operations and customers. The data that is around the business is not currently very delicious or available. People are picking at scraps all the time but they are definitely not satiated. Business analysts, project, product, and program managers (cooks in my scenario) are hired to prepare data-meals for the very data-hungry executives and managers. The managers are picky eaters and have high expectations of what you put on their plate. The job of the cook/analyst is to gather up the various bits (data-ingredients) and whip them into a lovely broth that the business can enjoyably consume.

Be Versatile or Be Gone

One of the keys to being a high-functioning technology consultant is to be versatile in your role.  You have to be able to do a lot of things well to make the client happy.  Common roles you (should) have to play well are Analyst, Builder, and Project Manager.  Here’s a quick description of each:

Analyst - Understand and define the problem using your skills of interviewing, math, statistics, process flow, data and information analysis.
Builder - put the necessary pieces together to create the solution.
Project manager – Integrate and communicate what’s necessary about the related parts of the project such that the involved parties understand what’s going on and continue to want what's being produced.  

In total, you have to be willing to do whichever job is necessary to get the job done and make the customer happy.  This requires experience, risk-taking, research, and networking.