A new study of Priscillian and Priscillianism is out. Intending to move past questions of orthodoxy and heterodoxy and look at Priscillian from a more local level as a nonconformist, Sylvain Jean Gabriel Sanchez considers the influence of gnosticism and particularly of Manichaeism on the movement.
My fascination with Priscillian has always concerned the questions of political theology raised by his trial and the dispute between the bishops and the civil authorities over his execution. In this, I take Chadwick's study to offer more of interest than anything else in English, even though a lot of the literature is more concerned with pitting Priscillian against the orthodox church hierarchy. Sanchez seems to want to move away from the disputes about doctrinal orthodoxy as well, although he will do so by considering the religious sources of Priscillianism itself.
Happily, Sylvain Jean Gabriel Sanchez has a very helpful website set up that is worth perusing. Amidst a lot of other useful information, he has even provided a bibliography of studies of Priscillian... going back to the sixteenth century.