Adobe did Intel-based Mac users a favor by releasing a public beta of Photoshop CS3. For those of us that have dealt with Adobe beta software in the past, we all knew you need to uninstall the beta software before installing the real thing, otherwise the installation will most likely fail. Unfortunately, that little bit of information wasn't clear to many first time beta users.
Here's how to uninstall Photoshop CS3 beta:
Launch the Adobe Creative Suite Installer. It's in Applications/Utilities/Adobe Installers.
Select Remove Adobe Creative Suite 3 Design Premium Components.
Click Next.
Make sure that Photoshop CS3 and any other CS3-related components are checked.
Click Next.
The installer shows a summary of components that are going to be uninstalled. Continue on to complete the uninstall process.
Once the installer finishes removing the Photoshop CS3 beta components you can safely install the shipping version of Photoshop or the complete Creative Suite 3 package.
If, however, the uninstallation process fails, you may have to resort to Adobe's CS3Clean Script application. It is more aggressive, and is designed to remove all traces of Adobe applications - although in my experience, no application fully removes everything Adobe installs. The only exception I have found so far is Apple's Disk Utility and its Format option, which has the unfortunate side effect of deleting all of the data, applications, and Mac OS X from your hard drive.