I think we did not see new Mac Pros and new iMacs because Apple wants to update them to use a retina display as well. I think it's more likely that Apple expect

I think we did not see new Mac Pros and new iMacs because Apple wants to update them to use a retina display as well. I think it's more likely that Apple expects the displays to be available soon than that Apple doesn't care about these lines anymore. If Apple wants to update the big screens, it will need to update the iMac and the Thunderbolt displays at the same time. Since the MacPro should be able to use the Thunderbolt retina display, it probably should be updated at the same time. I might be wrong that it's the screens they are waiting for, maybe it's the graphics cards, but I am sure all those product lines will be updated at the same time and they all will get Retina and probably within the next 6 months.