The 'whitey' tape is the latest tempest in a teapot. A few diaries looked at the issue, but i think they all omitted an important factor.
We all understand that if Clintons had the tape, it would have been released already. However, I think Sharris is wrong in the other side of the supposition: if GOP had the tape, it would not have been released already, because even though Clinton might be the weaker nominee, such a tape would amount to a nuclear weapon against Obama.
If GOP had the tape, they would be doing everything in their power to get Obama nominated, so as to slap him down with this tape in October, or at least after the election. If the tape were in GOP hands, spreading rumors about it would not be to the owner's interest. They would be keeping their power dry and playing rope-a-dope.
The rumors would only be useful if there is no tape, but the mere vague references to it can be used to put up smokescreen, hoping that people will assume there's no smoke without fire.
Of course it's always the possibility that whoever holds the tape is simply stupid...