I assume that there is a lot of breeding towards the goal of rose rosette resistance.
A possible alternate (less crowded field) goal could be resistance to rose midge. Apparently, the rose midge is proving difficult to control with to safe chemical treatments.
http://www.pghrosesociety.org/rosemidge.html
The following rose appears to be a good breeding starting point for rose midge resistant roses. It is supposed to be very resistant to rose midge.