I use GoogleNews as a Metric to determine whether I should spend much time on an ICT item, languages, platforms, protocols, you name it . I know it is not good to support the big bully, but only GoogleKnowsEverything.
In the case of XML technology, I look up OPML and OML, and have to conclude neither made the mark, as GoogleNews return nothing. -- dl
Have you got a better metric?