Favour composition over inheritance, in response to http://trycatchfail.com/blog/post/Globally-handling-status-messages-in-ASPNET-MVC.aspx

WithStatusExtension.cs

    public class TestController : Controller
    {
        public ActionResult Index()
        {
            return View("Index").WithStatus("Some message");
        }
    }

    public static class StatusResultExtensions
    {
        public static ActionResult WithStatus(this ActionResult result, string status)
        {
            return new StatusResult(result, status);
        }
    }

    public class StatusResult : ActionResult
    {
        private readonly ActionResult _result;
        private readonly string _status;

        public StatusResult(ActionResult result, string status)
        {
            _result = result;
            _status = status;
        }

        public override void ExecuteResult(ControllerContext context)
        {
            context.Controller.TempData["Status"] = _status;
            _result.ExecuteResult(context);
        }
    }