[SoftwareMaven]

Do you expect that any non-Apple device will be able to use iCloud?

Given that Apple is supporting Windows for Photo Stream and iTunes Match at least, I would say the answer is closer to yes than you are intimating here.

[num1]

I hadn't heard of that thank you for pointing it out. This does make things look more optimistic. I would still define it as vendor lock-in though. The iTunes binary might be available for Windows, but Apple still claims control over your experience and your data.

While they are in control of your data, you will be faced with a question every time you upgrade your hardware. Do you want to interact with your own documents and music using a clunky interface, or do you want to use an interface that makes you feel more in control and happier?

The above question is a little contrived, but I believe that it is fairly close to the truth, Apple has always been a company based on making you feel good.

[wtallis]

The photos and music are still stored unencrypted on your hard drives, and the metadata is embedded in those files, so no, they aren't controlling your data, any more than Dropbox does.

[CJefferson]

Do you think any Android phone, or Windows mobile, will be able to use iCloud?

Apple support Windows because there would be an uproar if Windows users bought iPods and iPhones and couldn't use them. They do the bare minimum they have to however.