Actually, it is new. While the Court has made plenty of minor exceptions to the exclusionary rule, it is the first time the Court has really bucked the Warren Court's Mapp v. Ohio ruling and refused to apply it to a fairly common situation.
All I have to work with here are your (overbroad) title and the sketchy AP report. And your reference to Mapp.
But the news here seems to be the lack of a knock requirement, not the conduct of a search pursuant to warrant.
Do you really mean to say that there is NO exclusionary rule for no-knock searches?