Q: A Warning: Syncing Photos with iTunes to iOS 8 Devices

See my note here:

A Warning: Syncing Photos with iTunes to iOS 8 Devices

If you need to sync your photos from either iPhoto or Aperture to your iPad or iPhone, and recently upgraded these devices to iOS 8, do not enable iCloud Library beta on these devices. It will disable syncing photos with iTunes,  and "My Photo Stream" will no longer upload from your Macs to the iOS devices.  You will have a hard time to get any photos to your iOS devices other than with Dropbox or Mail.

 

Apple has changed the status of iCloud Library back to "Beta" with the current iOS 8 release, and you cannot access the iCloud Library Beta in any way from your Mac right now without Yosemite and a matching Photos.app on the Macs. iCloud Library will only sync between iOS 8 devices. If you need iTunes syncing for your Photo Libraries, disable iCloud Library Beta again on the devices. Disabling will let you copy the library back from iCloud to the device.

 

See more here:  Apple Pushes iCloud Photo Library Back to Beta as SMS Continuity Delayed to October - Mac Rumors