Very, very interesting. I work in a company full of Ruby on Rails devs. Many also do some iOS development. But nothing that requires the significant performance advantage that one would receive from writing in Objective C. Almost all of them would be overjoyed to ditch Objective C at least most of the time.
Shouldn't the headline read something more like "Senior engineer confirms he is woking on MacRuby for iOS" -- didn't seem to me that he is implying that it is an official Apple project.