In case you missed the announcement, hidden amongst other Apple announcements, iTunes song sales have now topped 2 billion. That means an additional 1 billion were sold in the past 12 months. The data points graphed looks like this:
Make your own crystal ball projections….
Jason Ball 
I appreciate the link. My prediction is that they will top 3 billion songs by November.
If not sooner. What about video downloads? I’m convinced we’ll see equally impressive growth rates. Personally, I’m an iTMS junkie and have Season Passes for several shows…