The answer is it depends. DVDSP 2 and beyond support iDVD (iDVD 3&4) projects by direct import. You just start an iDVD project with the menu you want and save the project. You would then open the project in DVDSP. Unfortunately, iDVD5 projects are not supported, even with the upcoming release of DVDSP 4. I do believe however you can navigate to the folder where the iDVD themes are saved on the HD and use the backgrounds, etc. in DVDSP.