We've "known" this for a long time, but here are the numbers to back it up (and some cool visuals).
This is presenting a difficult challenge for independent devs and small shops. Do I build for the larger user base or do I build for the users who are actually going to pay? Right now, both platforms appear to be a race to the bottom (all the things are a free), so it will be interesting to see how/if that plays into Android's favor.
The flotsam and jetsam of a techie mind...