Simon Gathercole offers some very helpful analysis on the so called New Paul Perspectives, forwarded by chaps like E. P. Sanders, J. G. Dunn, N. T. Wright, to name but a few. The crux and bottom-line issue at stake here, is well described by Gathercole:

The difference between old and new perspectives can be summed up briefly. In the old perspective, works of the law are human acts of righteousness performed in order to gain credit before God. In the new perspective, works of the law are elements of Jewish law that accentuate Jewish privilege and mark out Israel from other nations. (Simon Gathercole, taken from the linked article at the bottom of this post)

The New Perpsectives single-handedly undercut the Protestant Reformation’s trajectory by re-framing the Pauline definition of justification by faith. Instead of justification referring to salvation from sin and to Christ, per the Reformers (i.e. Luther, Calvin, et al.); in the New Perspective justification is “faith” in Christ (evinced in obedience) which “merely” becomes a badge or identifyer for the participant—a badge that I am now a part of the covenant “People of God”. I.e. the implication, justification, for the New Paul advocates is not primarily an issue of salvation from sin and God’s wrath, but reconstitution by identification as the people of God in Christ. This is really a serious issue.

Gathercole, provides a balanced critique of this issue, and demonstrates, in my view, the weaknesses of the New Perspectives relative to some simple exegesis of some key Pauline texts. To assume that personal salvation, sin, and freedom from slavery to works-righteousness is not at issue for Paul and his discussion of Justification, in the New Testament, does not stand up under some simple scrutiny. Gathercole demonstrates this, in the following article (by the way he does a good job showing strengths of the New Paul as well). Here is the article:

What Did Paul Really Mean?

also for further exegetical argument from Gathercole see his synopsis: AFTER THE NEW PERSPECTIVE:
Simon Gathercole

and further Thomas Schriener’s: The Law and its Fulfillment: A Pauline Theology of Law