To what extent have C. arabica beans been replaced by rust-resistant cultivars? There have been articles in the news about coffee rust affecting coffee crops in many places. After reading this article it dawned on me that not only is C.liberica (resistant to rust) being exported in large quantities from some places (Phillipines, for example), Colombian researchers have developed resistant hybrids that may well be replacing C. arabica--to some extent-- in South America as well. 

If I go to my local coffee place and get a (relatively) expensive espresso my assumption is that the beans are arabica unless otherwise indicated. If you look at a futures contract for coffee, there is a big premium for coffee from certain countries, in part because it is assumed to be arabica. Is this still true and, if not, what percentage of coffee labeled arabica is actually arabica? 

My link is now broken and in response to the comments I am going to add links on efforts to (partly) replace Arabica with resistant species or hybrids. Here is one: Barista Magazine, resistant hybrids of Arabia-Robusta.
Even with the impact of below average crop yields from Coffee Rust, Arabica beans still make up at least 75% of the world's coffee crop. Although they are affected by the rust, Arabica plantations will tend to recover within a few years and go back to business as usual. 

CLR resistant varieties aren't without problems. They are still vulnerable to other desease that can have an impact on crops. 

USDA report on Coffee Rust impact to Arabica crops

2014 article on the Impact of Coffee Rust