I think it's going to be a brokered convention, which is exciting.
Baseless speculation, because a brokered convention can create almost any result: Kasich is the nominee, Rubio is the Veep pick. This maximizes the Ohio/Florida swing state potential while creating the most palatable general election ticket. Ted Cruz gets promised that he can be attorney general if they win.
I think it's known at this point that Rubio's time has come and gone.
Sanders is probably about 5 points off where he needs to be. There's reason to be more hopeful than the "Hillary is inevitable" story, but he's also running out of time. Blame Debbie Wasserman-Schulz for sabotaging him early.