iOS 8 and iCloud Drive
If you upgrade to iCloud Drive, you will only be able to sync with devices running iOS 8 or OS X Yosemite. As OS X Yosemite is still pre-release (and not yet available) upgrading to iCloud Drive will prevent you from syncing with Clear for Mac until both OS X Yosemite is released and you upgrade to OS X Yosemite.
Developers cannot work around the choice made when upgrading to iOS 8, so please make sure you pay close attention to the iCloud Drive screen shown after you update to iOS 8.
If you need to sync with devices that are not (currently) iCloud Drive-compatible, ensure you choose “Not Now”. this will keep iCloud’s “Documents and Data” sync feature enabled on your iOS 8 device so that you can sync with OS X Mavericks (and iOS 7 devices).
Update (2014-09-17): Caitlin McGarry:
You can go back and upgrade at any time, but unless you want a file-syncing nightmare on your hands, you’ll wait for Yosemite’s official release. You don't even have to take our word for it: Developers like Realmac Software and Bloom, which makes Day One have taken to their blogs to warn users about potential syncing problems and the lack of iCloud Drive support for pre-Yosemite versions of OS X.
Beyond the basic inability to access iCloud-stored documents on the Mac, this limitation also prevents you from working on iCloud-stored documents on both an iOS device and a Mac. So, if you’re a fan of switching back and forth between Pages on your iPad and on your iMac, you really want to postpone upgrading to iCloud Drive until Yosemite ships.
Update (2014-09-19): Apple:
iWork customers who use a Mac with OS X Mavericks or earlier will experience issues keeping their documents up to date if they upgrade to iCloud Drive via iOS 8 or iCloud.com.
If you update to iCloud Drive, you lose access from the iWork apps on Mavericks.
Mac users are better off waiting for OS X Yosemite to drop before upgrading to iCloud Drive, but iOS 8-toting Windows users are cleared for takeoff. Apple recently released an upgraded version of iCloud for Windows loaded with iCloud Drive.
Update (2014-09-20): Kirk McElhearn:
This belongs in the Department of WTF. How can Apple have allowed iCloud Drive to go live, hijacking the documents of so many people? Michael Cohen offers a matrix in this article, showing which types of devices can share files with other devices. It’s pretty sad that this has happened; Apple needs to release an iCloud Drive update for Mavericks now, so people don’t lose access to essential documents.
Update (2014-10-19): Michael E. Cohen:
Yosemite is now upon us, and if you are an iCloud user and you upgrade to Yosemite, you won’t be able to avoid iCloud Drive. In most cases, your documents should weather the transition intact, but if you also have an iOS device and you discover that iCloud Drive misbehaves on it in any of your iCloud-enabled apps, do the simplest thing first: sign out of iCloud on the device and then sign back in. This simple act might well brighten up an iCloudy day.
