The expression is "What's shakin'?" (not 'what') Walee Wang's meaning is correct: Has anything exciting/interesting happened? It's a very informal phrase and most English people would use it ironically, as a joke against themselves, as if they were pretending to be hip and trendy.

aha, I've seen that expression in The HBO series Big Bang Theory. Basicly means "Anything excited happened?" I'm no native English speaker by the way.

Oh thx man for help