According to
this timeline, from a right-leaning source, the story was first given to the press in November 2005 but the St. Petersburg Times did nothing with it (presumably because they felt those early emails weren't sufficient or perhaps they were protecting a local politician). It also has the emails being provided to the FBI (though it isn't clear on which ones) in June of this year.
So it sounds like there were attempts and opportunities for this to hit the press much earlier than now.