Apple has told 9to5Mac that that the company will be ceasing development of Aperture and iPhoto, offering Photos for OS X as a replacement, which was first shown at WWDC.
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.
Apple says libraries will be able to migrate across to the new application when the application ships. Apple is working with Adobe to offer a upgrade path to Lightroom. As noted by TechCrunch, Apple will offer a Yosemite compatibility update for Aperture, but otherwise development has ended.