Personally I think it’s another ploy to take the spotlight off of Biden’s mental issues. I think they plan to run the VP contest right up to the last day or two of the democrat “virtual” convention, then if Biden really screws up his acceptance speech, everybody will be talking about the VP pick and not the speech.
Personally I think it will Rice because it's the old Obama crew that is running the Biden campaign (and making all "his" decisions for him) and Rice was the ultimate Obama insider. But I guess will see whenever somebody decided to tell Biden who his VP will be...