If there's any doubt about the accelerating shift from traditional SLRs to more compact interchangeable-lens cameras, let the newly released Mac OS X 10.7.3 update put them to rest.
Of the eleven cameras whose raw image formats Lion now supports, six of them are compact mirrorless models. They are the Nikon 1 J1 and V1, the Olympus Pen E-PL1s, E-PM1, and E-PM1; and the Sony Alpha NEX-5N. All these models forsake SLR's flip-up mirror and optical viewfinder, enabling a more compact design.
Raw photo formats, available on SLRs and high-end compact cameras, leave the processing to the photographer rather than relying on the camera's assumptions about how best to make a JPEG. The result is better quality and flexibility, but more hassle for photographers.
It's also a hassle for software makers, because new cameras come with new proprietary raw formats whose inner workings must be decoded. Apple, unlike Microsoft, builds that support directly into the operating system so software such as iPhoto and Aperture can handle the images. To keep up with the unceasing parade of new cameras, Apple often releases raw support updates in between operating system updates. The raw support in the Mac OS X 10.7.3 update had been available since November for those who needed support sooner.