9to5Mac and MacRumors have reported that there may be an iCloud version of Photos in the works. Click either of those links or the screenshots below to see what they are reporting. (Thanks Matthew Morse for the tip)

While that may be true, let's not forget that Apple promised at least one maintenance release for Aperture to ensure Mac OS X Yosemite compatibility. In my mind, that would include the ability to publish to and read from iCloud drive, since that's what we're being migrated to in iOS and OS X.

I don't have any confirmation of this, but I'm expecting to see an Aperture update come immediately following the release of Yosemite. And just as an early warning, until you know that the Aperture maintenance release is available, you probably shouldn't upgrade to Yosemite.