"with the introduction of the new Photos app and iCloud Photo Library, enabling you to safely store all of your photos in iCloud and access them from anywhere, there will be no new development of Aperture. When Photos for OS X ships next year, users will be able to migrate their existing Aperture libraries to Photos for OS X.
Aperture on OS X Yosemite will support RAW v6, meaning new RAW support added to OS X will be available to Aperture users on Yosemite."
From an Apple spokesman, as published on DPR. The sky may not be falling as fast or as hard as you thought. Of course, if you have very old hardware that can't take the newer OS, you're not going to get Photos. But Aperture isn't suddenly going to stop working either, so you'll have time to plan a transition.