While watching the Bill O'Reilly show, I heard him say (several different times) "What say you?' He is an educated person so I am surprised to hear him use this term. It is correct?
Many TV personalities use some sort of "catch phrase" that becomes identified with them. For example, Walter Cronkite always ended his broadcasts with "...and that's the way it was (insert date)." At the end of the Huntley-Brinkley report, David Brinkley would tell his co-anchor, "Say 'good night,' Chet." So Bill O'Reilly has latched onto "What say you?" as his own catch phrase to not only get viewers/listeners to respond, but also to serve as an identity for his talk show persona.