Important note about Powerpoint 2007 and ShowCase
Yes, your ShowCase presentations should run normally under Powerpoint 2007!
However, you need to take some care when saving presentations from Powerpoint 2007. Use the option to save as "PowerPoint 97-2003 Presentation".
There is a new Powerpoint presentation format "pptx". It is a terrific new way to package presentations in a much smaller file size using Zip compression and an XML structure.
HOWEVER, the pptx files cannot include "macros", and macros are necessary for ShowCase windows to display. You will need to store your files in the usual ".ppt" format (save as "PowerPoint 97-2003 Presentation" ) if your presentation includes ShowCase windows in the slides (DICOM format images).
Powerpoint DOES NOT WARN YOU that anything will be amiss if you save a presentation with ShowCase windows in pptx format! Be careful or you could end up with a presentation that has all black images.
If your images in a presentation are in AVI, BMP, TIFF or JPG format, you can use the new file format since these images are not stored as part of the presentation but maintained in separate files.
And if you do store your presentation in the nifty new pptx format, be aware that you will not be able to easily move it to a machine with an older version of Powerpoint
For more information from Microsoft on portability of pptx files click here.