This depends on the final state of uispecs.

Are you sure the generic Settings API is the right place where
profiles should be accommodated? IMO it deserves own api.

here are 2 requirements for the startup profiles api:

1. The UI shows a build target that is built before execution. I need
to be able to select a build target (programatically) when creating a
new startup profile. 

2. I would also be useful to be able to filter the set of build
targets that make sense for a certain profile type. I realize that
some generic build targets (e.g. ant script) should probably never be
filtered out, but it never makes sense to set "Compile Classes" target
for a web module execution target.

The build target filtering can already be done via ContainersList and
mimetypes. For example, filter first on java classes mime type and
then on the build target mime type to obtain the set of java producing
build targets. 

Chris, I am aware of the filtering you describe. My point was that
there is no way to force the profile to restrict the selection to only
my filtered set of build targets.

BTW: I just learned that it is at least possible to get to the
selected build target:

private ProjectMember getBT (ProjectMember profile) {
  Project project = profile.getProject ();
  ProjectMember target = null;
  Object value = profile.getContext
().getObject("nb-projects-buildTarget", null);  //NOI18N
    if (value instanceof String) {
      if (value.equals("default")) {
        target = IdeProject.find (project).getDefaultBuildTarget
(null).getProjectMember ();
        }
    }
    else if (value instanceof FileSet) {
      Iterator it = FileSets.toFileObjectSet((FileSet) value,
false).iterator();
      FileObject targetFO = it.hasNext() ? (FileObject) it.next(): null;
      if (targetFO != null) {
        target = project.getProjectMember (targetFO);
      }
    }
    return target;
}

one more requirement from j2ee execution:

We want to be able to suppress compilation of selected build target.
The user should be able to select a build target and just execute it
w/o rebuilding and reldeploying it to server. 

Additional reqs:
http://projects.netbeans.org/servlets/ReadMsg?msgId=573585&listName=dev

(maybe dupl of something already described here).

As described in
http://www.netbeans.org/servlets/ReadMsg?msgId=619519&listName=nbdiscuss the
current work on projects prototype has been stopped.

--> VERIFIED