I don't know what the fuss is all about. All of a sudden the services we've all been using for the last 20 years are now called cloud services because they are accessible from all other the internet instead of just your company's internal network. Why are they even called cloud services? I mean, mail, calendar, contacts etc..? You've had that 'cloud service' for the last 20 years in the form of Microsoft Exchange.
Sync over the wire is the thing thats 1996, not over the air syncing. I am not saying you should all stop whining and use iCloud, no, please god no. I also appreciate my data and like to have it in my own hands and have set up an ESXi box with several servers virtualized on it to provide me with all the cloud-service you can ever think of, but all privately. You don't have to go through all the hassle because they've created something for you: OS X Server. You just run to the Apple Store, buy a Mac Mini with OS X Server on it, throw it in your network, configure some ports, which if you own an Airport, is done automatically at the click of a button. And off you go, private over the air syncing, all your data, in your own control.
And the new dumbed down version of OS X Server is so simplified you can run it along side on your client, no problem at all, as long as you don't turn it off. But who turns his non-portable mac off anyway.
Best of luck.
@DHoogs turning off iCloud will delete all iCloud's data of your device, the data that is allready uploaded to iCloud's servers will not be deleted. And upon deletion of all iCloud's data off your device your contacts that were not stored in iCloud will remain. It has been that way with Exchange servers, and it still is with iCloud. Basically iCloud is an exchange server for calendar, contact, task mail etc. The only addittion is some smart file-sharing.
