Status Quo: as of S2AP beta6, there are only two ways to configure the context path under which a web application is deployed:
1) if the deployment artifact does not make use of Web-ContextPath, the filename minus the extension will be used as the context path.
2) if a path is explicitly configured using Web-ContextPath, that value will be used.
Both mechanisms are directly tied to the deployment artifact.
Goal: the Platform should provide a means to deploy a single web application multiple times under different context paths without renaming or repackaging the original deployment artifact. This could be achieved, for example, via the admin console by supplying a context path when uploading the deployment artifact. The supplied context path would then override a path configured via Web-ContextPath and would preclude defaulting to the filename minus the extension.
The alternate mechanism could also be used simply as a means to override any pre-configured or default context path when deploying a web application a single time, in contrast to deploying it multiple times.