Overview
_service file seems to be useless here?
Why do you think so? It is a perfect way to obtain new tarball using "osc service dr" without need to surf sourceforge site.
It inded is useless, if you have url in the spec file just run 'osc service localrun download_files'
Sure, for this particular package I can. But the idea behind that some packages use download_files service, some others use tar_scm service, etc. And when I can run osc service dr for all packages then I don't need to remember the way of obtaining source for any particular package, which would require O(N) of my memory.
Well, apart from the useful/useless discussion, the changelog is missing about your addition of _service. It's silently sneaking in. That's not good, in anyway.