What I find disappointing is their focus on photo uploads. I think users really just want to pick a best of breed provider for major features like this in their lives, and Facebook has photos sharing locked up.
Dropbox has brought simple file synchronization between machines that are not necessarily on the same network, to the masses, but they need to do it in away that doesn't make you want to drop Dropbox when it goes wrong. I had a machine with Dropbox installed turned off for a year, and when I turned it on, it's clock was wrong, so when I updated the clock, Dropbox deleted all files in my Dropbox that were newer than the last time I had that machine running. What did it delete? Hard to tell. And Dropbox doesn't support restoration for folders, or points in time, just single files.