I didn't expect this. I thought Apple had a lot more penetration with pro photographers.
Aperture Vs. Lightroom: What Do the Pros Use?: "John Nack on a survey of 1,026 professional photographers in North America regarding their RAW processing software: 66.5% using the Photoshop Camera Raw plug-in
23.6% using Lightroom
5.5% using Aperture"
(Via Daring Fireball.)
This isn't helping me decide what my photo software choice should be. Why do we have to have so many choices?