Everyone has a different top 3 every day. I am not buying it. Hillary knows who she is picking and her team is doing a good job of keeping the secret and knocking us off their trail.
The people in her team who know who Clinton's decided (and she has decided at this point) is likely limited to Podesta, Mook and Huma. Obama told only Axelrod and Plouffe that he had decided upon Biden before he made the phonecall (five days ahead reportedly if we want to compare timeframes), while an inner circle of speechwriters received a shortlist of three (Biden, Bayh, Kaine) to prepare for. It's impressive that her campaign has avoided even a final shortlist leak though - CNN/AP/WaPo/NYT with their differing reports clearly know sh**t.