There have been sustained attacks against Sanders description of Second Temple Judaism as 'normative' Judaism, mostly by scholars studying Judaism. Jacob Neusner has led the attack (I use the word attack because much of Neusner's criticisms are couched in polemics) on the notion of an orthodox, normative, Judaism of the Second Temple period. Other prominent scholars offering the same sort of criticisms, with a little less polemic, include Martin Hengel (JTS 46), Phillip Alexander (JJS 37), and Jonathan Z. Smith.
One of the more interesting outcomes of these criticisms is how Sanders is accused (rightly) of describing Judaism as an outsider, and using essentially Christian categories to do so. Scholars of Judaism have never been tempted to describe the Second Temple period as a degenerative stage in the 'histories' of Judaism, for obvious reasons. This observation, along with the variegated nature of Second Temple Judaisms, led to a number of studies on what constitutes as a Judaism (see again Neusner and Smith). This of course has profound interest for those studying when Judaism and Christianity parted ways, so to speak. I am not trying to suggest that Sanders' 'New Perspective' is directly related to the discussion of the 'parting of the ways', but rather that the revolution that Sanders invoked made Christian scholars take notice of the rich complexities of Second Temple Judaism(s).
One of the recent attempts to illustrate the variegated nature of Second Temple Judaism(s) is book of collected essays entitled, Justification and Variegated Nomism. The editors did a magnificent job of rounding up the experts in a vast spectrum of fields, in order to show just how diverse the texts actually are. The insurmountable problem with this text is the puzzling way in which the various interpretations are co-opted by the editors 'post-script'. Certainly, Sanders is taken to task for offering a 'least common denominator' description of Palestinian Judaism, but others in the volume feel that 'Covenantal Nomism' works quite well as a short hand description, and wouldn't dispense with it wholesale. One wonders why in the editor's concluding section, such an unequivocally one-sided reading of the texts is offered, as if scholarship can now move beyond the Sanders revolution.
The positive and negative of these developments is that Pauline scholarship is no longer in a position to read the Jewish religion of the first century as a simple foil to Christianity, but likewise Pauline scholars can no longer assume that the backdrop of Pauline Christianity is always everywhere that of Covenantal Nomism. There is no escaping the Sanders revolution; it just means the task for reconstructing the back drop of Pauline Christianity just got substantially harder.

