An alteration of the phrase, "what's happening?"
Its earliest usage dates back to 1992 when
Ice Cube (best known for his lead acting role in "Are We
Done Yet?") inquired eloquently about the occurrence of a game of craps.
Tre: Whats the haps?
IC: I
don't know, but today seems kinda
odd
Tre: Do please elaborate while I listen to Footsteps In The
Dark by The Isley Brothers