Any project that lasts longer than a few months inevitably encounters some form of duplication from elsewhere. There should be a Metcalfe-esque law for that.
Love the enthusiasm! To us, anything that helps makes products work more seamlessly together online is a win for the web and the world we want to see.
It also seems like Dropbox is encouraging a different use case, in that the links they provide by default are Dropbox share links that route back to Dropbox, and even the direct ones expire after 4 hours. With Filepicker.io, we want to be a more complete filesystem solution, offering things like store to S3, read/write on the URLs, conversion, etc.