"Do you know what..." it drives me bonkers!

"Do you know what..." 

It seems to be the phrase of the year. Having replaced the ubiquitous "you know" which, for years past, fell from the lips of interviewers and interviewees alike on both radio and television, the new buzz phrase that I hear everywhere is, "Do you know what..." before the person speaking says what they want to say.

"Why?" I wonder, do people feel the need to prefix everything with such a buzz phrase... is it a verbal clearing of the throat?  Is it a nerve-suppressing prefix to speech? Is it just trendy and hip and what all the beautiful people are saying now?

Whatever the reason for this mindless phrase, it is driving me to distraction. I first heard it on the BBC's Strictly Come Dancing spin-off It Takes Two, where every comment seems to be prefixed by this inanity. Today I heard it on <gasp of horror> BBC Radio 4, that bastion of intellectualism and sensibility!

I suppose I should rejoice in the demise of "you know", which was amazingly irritating, but I regret that it has been replaced by another, equally irritating buzz phrase. Can people not just speak, without presaging their oratory with unnecessary twaddle?!