Actually the openSuse Build Service is more meant for packages that have to be reliably built for a multitude of systems and updated consistently across all of the distros, but adding a small cron job can pull SVN and push the changes to the Build Service, kicking off a recompile. I wouldn’t abuse it though.
I think we should sooner or later add a continuous integration tool, to check code submissions against the (until now inexisting) unit tests. That would also be able to create nightly builds ^^