Just a quick tip for those just wanting pre-view CR2 or RAW images without having to open them all individually in Photoshop. Just view them through Adobe bridge.
Open Adobe Bridge and navigate to the folder containing your RAW CR2 files. The thumbnails on the left will show Pretty much any format. Click on the CR2 or RAW images you wish to preview and examine them in the preview pane of Adobe Bridge. If you then find images you wish to edit further simply right click the image thumbnail and select open with Photoshop CS6.