It has been a long time since the Mac Pro has been updated. Although Apple is not in the habit of making announcements about forthcoming products, it would seem that they owe it to their customers to give at least a rough estimate of a release date. Furthermore, if they intend to abandon the Mac Pro, they should issue an end of life statement so that customers and prospective customers could plan accordingly.
Seems like it is coming - they took a patent out http://www.patentgenius.com/patent/7995350.html#show-page1
looks like the rackmount with no dvd bay