Dear LesCimes, Herb, Blick, and WeatherCat shutterbugs,
I put a few minutes into looking up alternatives to iPhoto and Aperture. This wikipedia article on Adobe Lightroom is interesting:
http://en.wikipedia.org/wiki/Adobe_Photoshop_LightroomThere is no doubt that Lightroom is a safe choice, but I really don't like the way Adobe does business.
The Mac World questions answered article mentions Capture One Pro:
http://www.phaseone.com/Imaging-Software/Capture-One.aspxIt is very expensive, but does seem really intended to give a professional photographer a good set of tools.
If you want to get something for less money ACD Systems sells a number of photo management packages from simple managers to products that also seem close to professional grade:
http://www.acdsee.com/They do appear to have some sort of option to import photos from iPhoto but I had to search around and I wasn't able to confirm it at the 100% level.
Anyway, some food for thought.
Cheers, Edouard