[Blunt]

Yeah, people probably use shastlivo differently but I do think many people use do svidanyia only when they intend to meet again or want to imply it, not in the literal sense but in the understood sense. As in not 'til our next meeting' like до встречи but 'goodbye' (for now). At least in my experience I've had Russians correct me on this.

Here are some Russians speaking on пока, удачи, счастливо, до свидания :

http://otvet.mail.ru/question/84542201