Who doesn't store files in "the cloud" nowadays? You could as well call this "Gmail for Hackers"... it would make as much sense as your "Dropbox" analogy.
Why don't you call it by name (i.e. "hosted RubyGems server") instead of confusing people and trying to piggyback on the "Dropbox" brand? Or do you think that your product isn't good enough?
I don't know why you would equate ruby gems with 'hackers' unless you really like people to be disoriented.