...I only own an iPhone and a mac notebook, but I still run Snow Leopard.
I also use the Microsoft Office suite, and so syncing iWork wouldn't even be useful.
The only thing iCloud has done is cause problems, deleting saved games (ie: Infinity Blade 2) and I can't find a single reason to use it, so I am going to turn it off and just back up on my computer only.
Are there any reasons why I would even need it at all?
Step back from all the hype. Apple traditionally gets people whipped into a frenzy ... Employing the "You've Got To Have This" technique.
Convincing otherwise smart people they need whatever Apples selling or they'll be really missing out. The tendency for Apple to exaggerate and over hype products is the norm. Apple is the master at marketing.
There's absolutely no need for iCloud unless you believe their is.
I'm not using it. Nor am I using Lion. All my Macs are fast, stable and trouble free on 10.6.8. Why change that just because Apples got something new to sell? I've already got a great network setup with NAS backup and more.
Perhaps at some later date after Apples got the bugs worked out of Lion I may change my mind. But presently it would be a step backwards for me.