[cough](http://cluster.co). I work on it. It's less "storage/archival" and more "private photo/video social network".
When folks sync their cameras and phones, they wind up with massive, disorganized mountains of images in the form of unwieldy iPhoto libraries. At a certain point (say, a year after the birth of a child) the task of going in and manually organizing photos, albums, sets or whatever is so daunting people just ignore it.
That was the promise of Loom - dump your photos here, and they appear automagically in a timeline you can edit and share. The execution leaves a lot to be desired, as I've suggested.
Cluster isn't trying to solve the "organize and share" problem, it's trying to make the stuff you share reach the right people in the right context. I think what Dropbox is doing fits their business model really well and adds a beautiful layer on top of your photos/videos in your Dropbox account.