I have noticed a very sharp drop-off in the use of the expression, "I'm just sayin," in the last year. Even the squarest, gayest morning host seems to understand that it has gone the way of, like, groovy.
I do once in awhile still see someone use it in earnest. They lob out an, "I'm just sayin'."
It's like, dude, you just said, "I'm just sayin'."