A large body of research results in the formal and informal literature suggests that Doppler radar data can be used to infer or directly detect tornadoes. Such a premise is part of the justification for the deployment of the NEXRAD Network in the United States. WSR-88D velocity and reflectivity data are primary tools (along with other inputs) used by forecasters at National Weather Service (NWS) offices in issuance of tornado warnings. The most commonly used signatures are the mesocyclone and the hook echo, both indicative of supercell storm structure. The smaller scale Tornadic Vortex Signature (TVS) is also used for warning decision making when range to the storm is not large...usually less than about 100 km. After about a decade of using these signatures, it is appropriate to ask, how useful are they? How can the signatures be best used? Recent research has given new insights into tornadogenesis. Do the new research results suggest different ways to use the already mentioned signatures...are there new signatures that should be considered? Comments are made about Doppler signatures and their best use. Answers are given to some of the questions posed above. Attractive areas for future basic and applied research are mentioned. Potential integration of NWS and television broadcast radars is highlighted