With the upcoming release of iOS8, you will be asked if you’d like to upgrade your iCloud to a new iCloud Drive. Sounds great, right? One snag in the near term is that you’ll lose access from your Mac(s) to any files you’ve currently got in iCloud until you upgrade to OSX Yosemite in the near -but not present- future.
To quote TUAW: If you use iCloud: you need to be really, very, no-I-am-not-exaggerating, super careful when you upgrade to iOS 8. Otherwise you could break iCloud syncing to all of your Macs.
While undoubtedly this will be fixed soon, in the near term, it could throw a wrench in your plans. They’ll at least say we’ve been warned.