As I understand iCloud it is syncing with the cloud. You don't have to "understand it" or "sell/explain it" to users, they will just "use it" with their Apps. I

As I understand iCloud it is syncing with the cloud. You don't have to "understand it" or "sell/explain it" to users, they will just "use it" with their Apps. In the demo the Apple VP made a picture with his iPhone of the toy car and then the photos were just there on the iPad. Without explicit upload. The same with documents in iWorks. I expect third-party developers will integrate iCloud rather quickly. That said: Dropbox can do some stuff like sharing files in the public folder with other people. I have friends who mailed me a Dropbox link for sharing photos instead of uploading it to flickr/photobucket/picasa/Facebook/iPhoto Gallery. I didn't see any feature like that in iCloud. It seems like an automagical data storage for Apps, but not like an individual "file system in the cloud".