Term that can be generally used in any context. Can refer to an activity, opinion or nothing at all. Given the right context, it could be compared to "what you up to"? Tends to be used more frequently in the United Kingdom.
Person 1: I'm thinking about going out tonight, so whatyousayin'?
Person 2: Yeah I'd be well up for that!
Person 1: Look at mah new shoes, whatyousayin'?
Person 2: Damn where'd you get those?
Person 1: Yo whatyousayin'?
Person 2: Say what?
Person 1: WHATYOUSAYIN'
Person 2: Oh, not much. Just hanging.