Why doesn the “openbib” class option have an effect on IEEEtran.bst?
At present, IEEEtran.bst does not output \newblock commands which are needed for an “open bibliography” format. Adding this functionality is not difficult. However, it does pose the question as to what is meant by an “IEEE style open bibliography”, including how to properly place the IEEEtran.bst additional fields (e.g., URLs, etc.) under such a format. Needless to say, an open bibliography could not be used for IEEE related work.