With iCloud Apple will potentially make money off the service because some customers will pay cash for extras (more space, more services, etc), but that's it.
Apple is a weird company because for all the eyebrows they raise with talk of closed systems and hubris and whatever else, they primarily make their way in the world by selling goods to consumers for money. The infrastructure enabling that is a crazy thing, but the heart of it is pretty old fashioned.
At the Keynote Stece Jobs had a bulletpoint "no Ads". I like that.
I do think my data is safe and private at Google (not so much trust in Yahoo and Facebook), but I am certainly looking forward to iCloud. Example: Gmail is a really good and free email-provider, but it also really sucks if you go through times that suck like a break-up and the adsense advertising is mirroring the unpleasant mails stored in your inbox.