Peter Cohen:
Apple’s shown over and over again that it’s willing to cause some short-term discomfort to users of existing products for long-term benefit. iMovie, Final Cut Pro, Pages, Keynote and Numbers — there are lots of examples where Apple has essentially scrapped the product and started over because a different path was chosen. And they’re doing it again with Aperture and iPhoto.
The difference this time, as Peter points out, is that Apple isn’t replacing its pro offering. My guess is that a lot of Mac-using professionals are going to be migrating to Lightroom.