To date I have not tested or made any changes to the actions to work specifically with Photoshop CS5. Even so, the early reports that I'm getting back from users that have converted to the new Photoshop CS5 - which, by the way, is totally awesome!! - is that the actions work with no modifications needed at all.
Even so, it's important to remember these points...
The retail package that is delivered to you includes an installer that is designed and tested to install the application into Photoshop CS4. If you install CS5 and then run the Greeting Card installer, CS5 SHOULD recognize the actions and load them into the CS5 Actions Palette.
If not, you simply go to the Actions Palette in CS5 and click "Load Actions...". Then navigate to the Greeting Card Actions file. To find the file check out the support document "Actions did not automatically install"
I have not yet worked on the One-Click Panels which are no longer Beta and now a part of the retail package so you will need to run the Greeting Card Designer from the Actions Palette directly.
I hope to have get a specific CS5 version in the next few weeks.
Thanks...