The major scission in Islam is between the Sunni, those who believe Mohammad received a definitive final revelation, and the Shia, who believe that there will be further revelations. While this manifests primarily as a power struggle between Saudi Arabia and Iran, and is obviously adulterated by historical traumas and social antagonisms, the purely theological aspect is too often ignored.
One has no choice but to side with the Shia on the theological grounds: Mohammad did not receive a final revelation, there have been and will be more prophets. However Shiism within the bounds of Islam is not radical enough. It seems that a major criterion for recognizing a true prophet in the contemporary world is a lack of strong affiliation with any of the seven major world religions.
A list of candidates: Simone Weil, Cornell West, Joseph Beuys, Gilles Deleuze, Helen Schulman, William Blake, Ken Wilber, Maharishi, Olivier Messiaen, Valentin Tomberg, Franz Rosenzweig, Karlheinz Stockhausen, Alice Coltrane, Napoleon Hill, Ken Wilber, Karl Marx, George Maciunas, Ann Lee, Jacob Boehme
What criteria exactly can be used to articulate a lineage of Greater Shia? Is it possible to articulate a set of these? It would be ideal for them to be strong enough that some apparent candidates ultimately must be left out - mere religious zealots, on one end, who merely reinforce the false hegemony of a bigoted value system with their enthusiasm, and mere 'geniuses' on the other end, who legislate a new transcendental horizon but do so in a way that is impoverishing to love, or reason, or the object of ultimate concern.