Not only is K&R _the_ book for C, it's an example for engaging, lucid, just-right technical writing that any technical manual should strive for.
We can hope that they might receive similar treatment as John Ousterhout's "Tcl and the Tk Toolkit" did. JOs work (including TatTT) is often held up as excellent writing as well. The second ed. of that book was updated by a group of experts w/ JOs blessing, but w/o his participation if I understand correctly. Indeed @davidw was a contributor to that project ;) (thx. david.)
Then again, so is AoCP.
Wrox is skinning a different cat by trying to provide the FM which no longer comes in the box.
Ritchie knew how to provide just enough back in the days when just enough covered the vast majority of cases.