This summer on a flight back to Chicago, I had the pleasure of reading an article that had been recommended to me long ago. It was an analysis of the whole Federal Vision and the New Perspective on Paul and a comprehensive source-checking of the whole deal.
In short, after reading it, I realized I needed to publicly retract my earlier concerns of NT Wright. While he doesn't like the terminology of "imputation," it is clear that he still affirms the idea behind it, and thus would affirm the traditional solas, specifically faith alone and Christ alone.
My personal support of the Federal Vision still stands. I think everyone who is critical of the FV should read the paper first. I think it lays everything out clearly and demonstrates that it is actually entirely within traditional orthodox formulations. We can disagree, and disagree vehemently, but I don't think this is a wolf-sheep disagreement.