If you need to import all of the pages from multiple PDFs into a PowerPoint presentation, Lori Kassuba has created an action that will do it. See the post named, 'Convert PDF to PowerPoint' on the Adobe Actions Exchange. Download the .sequ file named 'temp_file_Convert_PDFs_to_PowerPoint1.sequ' and simply double-click on it to import it into Adobe Acrobat. It will appear in the Tools menu

Click on the action and you will given the option to process one or more PDFs.

A PowerPoint file will be automatically saved to the same folder as the source files with each page of the PDF saved to a separate slide.