Text, images, videos up to and including the occasional rare film, lots of PDFs (usually small), sometimes a PowerPoint or an Excel spreadsheet, used to also do source code and builds and stuff before GitHub... and if I had faith in them being more useful, as opposed to just backed up, I'd probably dump a whole bunch more in my semi-organized DropBox folder.
So for my use-case the Organizer App would have to be able to deal with lots and lots of data of various types, occasionally including multi-gig files like the rough cut of a film, and also know when I "mv this ~/Organizer/that/" -- a tall order, I know. But with storage so cheap these days, I still dream of that.