A French article from 2007 is now available online: David Bisson, "Soufisme et Tradition," Archives de sciences sociales des religions 140 (October 2007), pp. 29-47.
The article is a good introduction to "Guenonian Sufism" as "the last initiatory possibility in the West." It covers Abd-al-Wâhid Pallavicini especially well, focusing on his development of a Western Sufism which is Christian in its culture, European in its geographical location, and Guenonian in its "metapolitical projections."
One interesting detail for those who see Guénon as Muslim before his arrival in Cairo (which I, for one, do not): Guénon wrote in Orient et Occident (1924) « il ne nous paraît pas opportun de s’appuyer principalement sur l’ésotérisme islamique ; mais, naturellement, cela n’empêche pas que cet ésotérisme, étant d’essence proprement métaphysique, offre l’équivalent de ce qui se trouve dans les autres doctrines » -- that is, "it does not seem to us appropriate to rely principally on Islamic esotericism, but, naturally, this does not prevent this esotericim, being properly metaphysical in essence, from offering the equivalent of what is found in other doctrines." Hardly the words of a Muslim.
Thanks to HF for drawing this article to my attention.