As often as Dropbox has been courting serious cloud storage users with Dropbox for Teams, it doesn't feel that the name reflects the company's loftier ambitions -- so it's giving the service a rebranding. Now called Dropbox for Business, it's pitched more directly at the suit-and-tie set. There's more than just talk involved in the new strategy, though. The shift also sees Dropbox build in identity management from five providers so that Dropbox users don't have to sign into the service