I just purchased Elements 10 from the App Store and I can't import any photos from iPhoto or even from pictures stored in a folder on the hard drive. I am running the new Mountain Lion OS with the updated iPhoto.
I'm not sure what you mean about "importing" photos. The app store version has no organizer so there is no question of importing anything. For files not in iphoto, just go to File>Open. For files in iphoto you can either set PSE as your external editor and send the photos from iphoto, or export the photos from iphoto to the desktop, open those in PSE and edit them, save your work, and import the edited photos as new files to iphoto.
Europe, Middle East and Africa