Lyric discussion by Nexus7 

Cover art for Waiting for the Cloud lyrics by Legendary Pink Dots, The

I think this song is about poisoning via pollution, and waiting for the inevitable nuclear bomb to just finish it all off. The cloud being a mushroom cloud. Also the last verse denotes the class division which would occur in such a scenario.

@Nexus7 the "cloud" actually refers to the Chernobyl disaster. 1986.