Of course the liberal bloggers and websites will jump all over any kind of negative news they can associate with the conservative media giants. They will of course ignore that the same negative news applies proportionately to their own heroes and icons. From October 2010 to October 2011, Rush Limbaugh gained listeners and, so far as I know, has not been disenfranchised by anybody. We are, however, in a non election year, and the GOP primary race has been anything but exciting over the last months. All media goes through ebbs and flow and a 30% drop (which is grossly exaggerated by the way) is not a cause for alarm when producers can see that it is pretty well across the board.
Look for the ratings to all spike again when the 2012 election cycle really begins to heat up and people are hungry for information.
Meanwhile, Rush is in absolutely no danger of losing his crown and number #1 position for as long as he wants it when he can produce numbers like this:
From Talkers Magazine, the "bible" of talk radio: