When deciding whether or not to run, one thing is certain: Hillary is in it to win it. If she doesn't think she can win, she's not going to spend the time, money, resources, and energy. Better to focus her mind and talents elsewhere.
While it cannot yet be known if Clinton will seek her party's nomination in 2016, it is reasonably clear that if she runs, she will be the strong favorite for the Democratic nomination and have a good chance of beating any Republican opponent in the general election.
Please Joe. Please Andrew. Please Martin. You are all talented and have awesome resumes. But, none of you have the charisma to spark a movement, to inspire the selfless volunteers required to overcome Republican lies and largesse. Hillary Clinton does.
Biden's active appearances at black and Latino gatherings, his rough language and his policy expertise are a huge plus for Obama in a down and dirty campaign. Any talk about dumping Biden is just that: talk.