PCs get access to iCloud Drive before Macs
If you’re a Windows user with an iPhone then you’re clear to enable iCloud Drive, but if you use a mix of Windows, Mac, and iOS then it’s worth waiting for Yosemite. If you don’t wait then you won’t be able to sync application data on a Mac until iCloud Drive is available with Yosemite. It’s an unusual move for Apple considering the company usually provides features to OS X first, but, asArs Technica points out, iCloud for Windows is still less functional than its OS X equivalent. iCloud for Windows still lacks iCloud Keychain syncing, a Find My Device function, and an option to sync notes directly. If you’re interested in enabling iCloud Drive then Apple’s iCloud for Windows update is available immediately from the company’s support site.
http://www.theverge.com/2014/9/19/6508795/icloud-drive-for-pcs-before-macs