I was in Pacifica, CA today for an appointment and had a chance to test the Canon's 5D Raw format. I must say, it was quite exciting to attach my 17-40mm f-4 zoom to the 5D and see the world full frame at 17mm. The 5D kept up with my pace of shooting and didn't slow me down as it recorded in Raw.
Processing the images was another matter. Adobe Bridge couldn't generate thumbnails for the .CR2 files (Raw on the 5D), nor could iPhoto 5. I could open the images by dragging them to Photoshop and editing in Camera Raw 3.2. But to browse the thumbnails, I had to use Canon's Image Browser application.
I'm hoping that we'll see updates to Bridge and iPhoto 5 soon. In the meantime, my workflow is a little clunky for Canon 5D Raw files.