Yes, he is ****, but that's not really the issue. I don't watch any of his shows, but should be be sacked on the basis of these comments? Well, personally I think it was a pretty dumbass thing to say but that, no, he shouldn't be sacked because his programmes (that I am aware of) have an adult audience and (I think) he gave the interview to a pretty adult magazine (Marie Claire).
I think it would be a lot different if he presented, say, CBBC or if he had made the comments on air or at a BBC press conference or any official capacity. I suppose you could argue that it was, in a way, because he only got the interview because of his role as a presenter, but you know what I mean...
I don't condone drugs and they are overrated, but freedom of speech and all that. If he wants to rave about how "fun" they are then let him, perhaps he's always on them when he chooses to wear those hideous suits he seems to like so much...inhibited judgement and all that...