What is a good RAW File Processor/Developer/Editor for Mac?
Apple iPhoto '11

Let's not forget that Apple iPhoto '11 costs $15 in the Mac App Store, and that it has processing tools for RAW as well as frequently-updated profiles for working with many makes and models of cameras that produce RAW image files.

Google Picasa

Google Picasa is free and supports many RAW formats.

Canon Digital Photo Professional

version 3.11.26 is compatible with Mac OS X Lion. If you already own an earlier version that came with your Canon camera, you can download the updater from canon.com for free. Otherwise, here is how you can get it:

Canon Digital Photo Professional comes on a CD with a suite of programs called Canon Digital Camera Solutions Disk ver. 38.1.

I recently bought a used Canon Powershot G10 whose seller did not provide the original software sold with a new Canon. So I called up Canon's customer service, explained that I bought a used Canon, and asked them if I could purchase their tools on CD. They sold me the suite for US $20 plus tax and shipping (it came to $27). 


  ...you may purchase the latest Canon Digital Camera Software Solutions
  disc for your camera through Canon USA's Customer Support Center at
  1-800-828-4040. Residents of other countries should contact their
  regional Canon customer support center for further assistance.


I installed the whole suite on Mac OS X Lion, then downloaded the latest updates from canonusa.com to make sure they were compatible with Lion. 

The suite includes Canon Digital Photo Professional, for processing RAW images, a batch-file processing utility called Canon Digital Photo Professional Batch, the Canon Image Browser for general photo management, and Photostitch for making panoramas.