Well as I understand it, the hybrids are an extension of "The One God". The theory that Baltar who is one of the final five and existed before is a good twist but not one that has not been used before. For example in the Matrix, Neo is the most recent manifestation of the anomaly, and his journey of self-discovery took time, suffering, and love. BSG follows the same theme of this has happened before and will happen again. This time who is the most "human" and resourceful person, that person is the "Chosen One"--Gaius Baltar. The incidental hero and villan at the same time. By showing he is a cylon does not diminish his responsibilities or the show, it just shows how similar cylons and humans really are in the end.