My Suggestions for iPhoto:
1. A folder management system that actually allows people to navigate through it in the Finder. I know that iPhoto is supposed to replace looking for photos in the Finder, but still - iTunes bothers to have a very nice folder system.
2. A search bar in the top right hand corner that allows searching names, keywords and comments. And they HAVE to change how Keywords are added/deleted - it is WAY too slow and complicated at the moment. Splitting them into groups of "People", "Place", "Occasion", etc. would help. And letting users create/modify their own groups. But having to go through that awful palette window when I have tons of Keywords is a serious pain.
BTW, I've heard the iPhoto library can be searched through Spotlight. Can anyone comfirm whether it can find photos by keywords or names?
3. As others have mentioned, give the titles I give to my photos back to their original file.
4. Improve the books! Create a gallery of clipart/objects that you can drag in. Things like beach balls, flowers, etc. to decorate the pages.
5. In slideshows, allow a stretch-to-screen for vertical photos, but don't do it for horizontal photos.
6. Sync the iPod Photo right in iPhoto! None of this iTunes Photo business for us Mac users. And allow Photos from the iPod Photo to be dragged right off of the 'Pod and into iPhoto without having to go into the harddrive. After all, as Steve said - no copyright issues.
7. Definitely add some more minor-editing stuff. Things like rotating and cropping the photo to be straight (ie: when things in the picture are slanted), and more filters. This is bridging into PhotoShop Elements territory I know, but it still wouldn't be enough to discourage me from purchasing Elements.
8. Allow photo slideshows to be saved as Quicktime movies and easily put on a .Mac homepage, ala iMovie.
9. Fix the bugs! Often when I crop photos/red-eye them, the changes don't show up, the photo just zooms out. I have to switch back to browse mode to see them. And it's not performance - I'm on a G5! And often when I click the triangle by Library to see the calendars, there's a blank spot below the "2004" calendar, with no icon and no name. When I tried deleting it, iPhoto crashed.
10. Burn CDs that Windows users without iPhoto can still easily navigate.
That's all I can think of at the moment - I like iPhoto a lot, but it is still far from perfect. I've submitted all of these to Apple before btw.