Is EditorBuildSettings deprecated?

EditorBuildSettings.scenes gives you a list of the scenes that the user has selected in the Build Settings window. This is a useful value for continuous integration scripts, where you need an array of scene names to pass to BuildPipeline.BuildPlayer.

For example:

string [] scenes = EditorBuildSettings.scenes
  .Where (s=> s.enabled)
  .Select(s => s.path)
  .ToArray();
BuildPipeline.BuildPlayer (scenes, "build/", BuildTarget.StandaloneWindows, BuildOptions.None);

Currently (April 2016, v5.3) EditorBuildSettings is undocumented. It was documented in previous versions, for example here: http://docs.unity3d.com/412/Documentation/ScriptReference/EditorBuildSettings-scenes.html

My question is; has it been formally deprecated? Is there a replacement I should use instead.

I think it’s deprecated and you should use UnityEditor.SceneManagement.EditorSceneManager

Unity 5.3 introduces the new Multi Scene Editing that’s why the old classes are deprecated. Check the Unity 5.3 Upgrade Guide → Multi Scene Editing