I'm excited about SOA repositories, no really I am, really. Phil states "What's less clear is what a successful SOA repository actually looks like." I would add its pretty unclear what a successful SOA looks like. In fact if you ask ten different people what is SOA, you going to get some interesting answers.
If you are new to SOA, and most of us are, I would suggest concentrating your efforts on writing good services first and understanding what a good service is. I do think repositories are very important and will become more important as services continue to grow within and outside of organizations. But I still think we have a lot to do on the services side first.