Bernie might win the next couple of primaries, but ultimately it'll become clear Hillary has it. He will stick with his campaign, though, to make sure his issues are being heard and discussed, and that's OK and good for Dems and progressives - we need to be challenged on the important issues. But in the end, he'll not only back her up, but will go to great lengths to convince his supporters that they need to vote for her to stop the GOP from taking over for the next 2-4 years. It'll be a tough sell, since there are so many "Bernie or nobody" people out there, and it's discouraging (let the radical right eat their own - we need to come together here).
Trump is out, but he's unpredictable and things could go a few different ways. He'll win a few primaries, sure, but as the real thought of him being the candidate starts to sink in, things will change for him. In the end, he'll either drop out (he really doesn't want the job anyway), or he just won't get the delegates for the nomination, or he'll run third party (which will quite nicely divide the conservative vote and give Clinton the win regardless), or he'll fight it to the convention and the establishment won't let him have it, forcing a brokered convention (which he won't win).
That said, Cruz will not get the GOP nomination. He's either going to really stick his foot in it and do or say something so tremendously stupid that he can't get out from under it, or the less Tea Party-ish in the party will come to the rescue. It may even come down to a brokered convention, but in the end, I'm predicting Rubio will get the nomination. (I would actually enjoy watching a Clinton/Rubio debate.)
And in the end, Hillary wins it.
Now, as for the VPs... ;)