Also on the core image hit parade is
Image tricks which seems to run just fine on my I ghz eMac. Quicktime 7 and the Tiger version of Preview also use core image
I think it's still very early to start looking for a major core image 3rd party software revolution, but it is pretty impressive, powerful technology. And there's still a long ways to go before we actually have Leopard in hand (which I'll bet expands core image even more into the UI) so it's likely developers of graphics/video oriented apps will have plenty of time to discover it.
Aperture was a good example for Apple to show off core image in a signature, high-end pro app. Eventually, developers will look at something like Aperture wonder "how did they do that?" and discover Tiger's core image api's. So Aperture is at least one way where Apple can demo core image and say, look, see what you can do? Kind of like the way Spotlight is used in System Preferences. I think it was more of a technology demo than a need to "search" control panels. But Spotlight is pretty nifty in System Preferences, not only with the ability to recognize MS Windows terminology-based queries, but also the marriage of the search feature with the the little graphic presentation. Pretty cool to do a search than have the result icon "spotlighted" in a graphic. So Tiger has intro'd some pretty cool stuff under the hood; it's up to developers and their imagination to take advantage of it.