[gustavo_duarte]

But why can't Dropbox become the main provider for this fully cloud-hosted architecture? So I keep my cloud files in Dropbox, and grant my cloud apps access to subsets of those files. Then they would truly be the "filesystem of the web" and the growth/profit prospects are rosy.

For example, http://leanpub.com/ uses Dropbox in an interesting way. As Dropbox beefs up their API and adds features, I think there are many interesting growth/monetization possibilities. I think the main danger is the competition from Google/Apple/MS.

[wavephorm]

The main danger for Dropbox is the commoditization of cloud storage, and filesystem abstraction. Dropbox style sharing going to be commonplace, everything will interact with the cloud, and web apps will abstract data in ways that make the conventional metaphors of files and directories obsolete. Plus as Amazon improves their API's and competitors emerge, Dropbox will get squeezed from every possible direction. They should pump and and dump while the market's good.