Cloudup was acquired by Automattic a few months ago and will continue to be available independent from Wordpress. http://techcrunch.com/2013/09/25/automattic-acquires-file-sharing-service-cloudup-to-build-faster-media-library-and-enable-co-editing/
I love Cloudup - got an early invite some time ago and have been using it ever since. It's pretty unique because it uses Node so the site is snappy and responsive and allows you to hand out the link to a file that's still uploading it.
Interested in where Automattic takes it, could be quite useful in their product lineup.