The current competition between notebook-dedicated optical-drive manufacturers will lead to "end of life" of Combo drive by mid-2005. At that time, the standard model installed on notebooks should be a 8x DVD burner. High-end notebooks should be equipped with multi-format, higher speed and DL DVD burners.
Let's expect that the future iBook revision in few months will be the beginning of the "all DVD burner" for Apple notebook machines.