I don't think melody is dying, it just has gone out of fashion as a stylistic means for some pop music - especially anyhing with a dance-electronica influence. People have also gotten used to simple melodies to the point where anything overtly melodious is quickly qualified either as "sounds like a musical" or "a Whitney Houston-type ballad". Funk und rap have become major influences on modern pop music and they generally don't feature a dominant vocal melody (but then neither did most traditional blues).
You don't hear a lot of Robert Flack - Killing Me Softly-style opulent melodies on radio - and if you do it tends to be an oldie.
But it's all relative: Holding on to one note can actually sound quite melodic if you have changing harmonies...
As a bass player, I work with that a lot. I hold on to notes where the band changes harmonies and I tend to augment with thirds, fifths, sixths and sevenths where they stick to a note or I play harmonies to their riffs. What I don't like is follow slavishly all their chord changes - that has me generally exclaim after a while: "Am I your friggin' E string tuned down an octave or what?!"