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
.. I had a friend in high school who would say this .. short for "What's happening?" .. saves one syllable and creates a noun .. actually it's use goes back to Shakespeare .. Hamlet at Ham IV.iii.70 "Howe'er my haps, my joys were ne'er begun."