How can I launch an Automator workflow upon import in iPhoto? I use iPhoto to import images from my iDevices and the photos go to the iPhoto library folder.
When I import from my DSLR, I place photos in a folder I organize myself by date and events.
I would like to automatically copy the imported photos in iPhoto to my folder so that all my photos can be found in the same place.
Is is possible to launch an automator workflow upon import in order to perform this task?
As you don't seem to use the iPhoto library at all, you should use Image Capture instead. It allows you to put your picture directly in a given folder.

You can also create a "transfer module" with automator which can be set to run after an import using Image Capture with imported pictures as input. Thanks to this, you can create an automator process to arrange them in folder as you want.

Image Capture is also scriptable with AppleScript, you might want to take a look at its dictionary if the GUI or Automator don't provide enough flexibility for you.

If you want your pictures both in iPhoto and in your folder, you can configure the automator process to add them in iPhoto once imported in your folder with Image Capture. Lots of workflow are possible, it depends and what you exactly want to achieve.