There's another reason the term "guy" is particularly approprite for journalists referred to in "Downing St. transparancy". Did T.S. Elliot have today's journalists in mind when he wrote "The Hollow Men"?

 'A penny for the old guy'
  We are the stuffed men
  Leaning together
  Headpiece filled with straw. Alas!
  Our dried voices, when
  We whisper together
  Are quiet and meaningless
  As wind in dry grass
  Or rats' feet over broken glass
  In our dry cellar ...
I know of few if any better descriptions of the complacent "guys" who get their information from media kits and their quotes from press releases, I don't know . The word fits to a "T."