Amazon has given me the privilege to test their new service Zocalo, which is like a nice dropbox alike frontend for S3. My first initial feeling is that the whole thing is really, really fast! The upload or download seems to be faster than dropbox or box. The user experience is pretty straightforward and simple, as it should be.
Currently there are only a small set of features; to share and review documents (and having that as Word comments), but I’m expecting in the near future more dropbox options to share folders with other people or more granular actions to documents. Maybe a google docs live collaboration system ? The 200GB per user really do the difference in corporate or even personal environments. Also, they already have their sync tools available for desktop users.
If we look at it, Dropbox is a nice interface for S3 and Box.com started as an interface to S3 as well, so there’s enough space for Amazon to move around and create something better.