Why do I want ICloud.?

There's an overview of what iCloud does here, including a video: http://www.apple.com/icloud/. If you have multiple devices iCloud will help you keep your data consistent as you make changes on any one of them. It will also stream photos between your devices, and allow you to share your photos with others. It will also automatically back up your device daily.

You may also find this page helpful:

http://rfwilmut.net/icloud

What if I don't want iCloud? I'm perfectly happy with organising my own data. I really don't need servers all over the world to interfere with my private data. We all know what can happen. Despite the strongest promises of officials.... So this not the answer to the question. iCloud is an privacy damaging, environmentally very unhealthy technology push! Shame on Apple!

If you are on Lion or Mountain Lion you can sync your Mac with your iPad/iPhone using iTunes and there is no necessity to use iCloud if you don't want to.

If you are on Mavericks, syncServices (the framework which enabled syncing via iTunes) has been removed and you have to either use iCloud, run your own WebDAV server (not easy), or use a separate third-party service such as Fruux (which of course is still syncing via the 'cloud', just a different 'cloud').

That's hardly a help. It's stating what I already know.

Apple should have announced loudly they were going to cripple users with this new MacOS.

I am really really gutted by this force step back in time to the era when syncing didn't exist. :-(