We just added author number 86,724 to the Roster of Champions, and signed up our 1,100th Young Writers Program classroom!
Look at those numbers climb. There is a thread in the forums with estimates for the total number of writers for 2009, which range from 120,000 (a little low, I think, with how many there are so far) to something like 250,000 (a little high, I think - but wouldn't it be fun to be wrong).