B) ISP files suit, argues 'this ain't constitutional, we shouldn't have to comply.' DoJ disagrees.
C) FBI counter-files, asserting that even if ISP prevails in step B), it should comply in the meantime rather than temporize pending the outcome. I can understand why they would, since they may in good faith consider time to be of the essence in obtaining the information they seek - which is part of their job, after all.
I'm not that troubled by D, insofar as undercover operations realistically require a degree of secrecy. What was troubling about the NSL regime was that it asserted this secrecy by default; I expect that in the future the government will still get NSLs but will first go through something like the FISA court and essentially ask a court for a gag order, presenting evidence under seal. This is IMHO how it ought to have been from the start.