About the cloud...
Just for those of you who are uncertain about what iCloud could be in the end: Think about what the cloud stands for, where this terminology comes from.
For those who think that the cloud is the Internet, think again. Think not different for once.
I used to work for a Tier 1 telco/ISP. The "cloud" traditionally referred to the PSTN (public switched telephone network) and then eventually the network of ATM packet switches when the backbone providers migrated to a data-based infrastructure for telephony and data.
The "internet" refers to a protocol, an agreement between networks to speak a common language. But colloquially it refers to the internetwork infrastructure, the top packet-switched layer of which we in the telco world coined the phrase "the cloud" to refer to.
So in today's use, "cloud" computing refers to Software as a Service (SaaS) schema which involve applications and data accessed/stored outside the enduser's LAN, WAN or Frame Relay, rather than client-server relationships that are under one roof.
E-file by Intuit (the company I work for) is an example of SaaS, as is TurboTax Online.
Why is it relevant? Because iCloud is basically going to mark the transition from accessing duplicated or shared libraries stored physically on a LAN to accessing your library whenever, wherever and however you want... over multiple types of mobile devices, multiple transports (wifi, 3G, 4G, etc.).
This will be a benefit to mobile computing for one major reason: It will reduce flash storage requirements, possibly enhancing battery life (though losing some to the energy cost of wireless transmission), but mostly lifting the barrier to the form factors and sizes that mobile computing devices can take on. Additionally, you wouldn't ever worry about your data becoming corrupted... and Apple need not multiply its storage and backup times the number of cloud customers, because it can serve multiple customers from a few locations... with some of the most impressive global load balancing of any WAN I've ever seen (think about how rarely iTunes ever lags, relative to the number of customers it serves worldwide).
In three years, you'll not worry about forgetting to sync Finding Nemo 12 .... you'll stream it to your car over 4G LTE and your kids will stop screaming. That convenience, and convenience of access to an unlimited number of titles regardless of device storage capacity, not waiting to sync up content, etc. is worth billions of dollars.
