Trump is really rocketing nationally. See how quickly he closed the gap with Clinton: he's cut a 16 pt deficit to 2 pts, and there's no reason to believe he can't climb higher:
1. Clinton's handling of the emails thing
2. People know him, know he's an asshole, so more exposure isn't going to reveal anything new.
Sanders is doomed:
1. The sharp downward trend for Hillary, matched by Sanders going up, seems to have stopped, and they have stabilised at 50 and 25.
2. In polls vs the Repub candidates, Trump just overtook him (+2 from -2 a week ago) and again, as above, there's no reason for Trump to fall, but with a concerted smear campaign revolving around "socialist", I"m sure Sanders will go down nationally.
Biden's numbers are spectacularly good, he actually looks like the safest bet right now.
Another very interesting thing is Ben Carson; he's showing great numbers in many states, including NC, and he has virtually no unfavourables. Could also split the black vote in a national election? (he's tied with Clinton in the polls you just showed, the best of all Republicans). On the other hand, like with Sanders, the spotlight should harm him.
The other Republicans are collapsing everywhere, Sanders and Bush are virtually tied, and Rubio is the only other one with decent numbers vs Democrats.
At this (very early) stage, I'm predicting a Republican victory vs Hillary. She will win the nomination unless she collapses spectacularly, and there are seemingly enough anti-immigrant votes coupled with a steady deterioration of her image to get the Republicans through.
I just hope whichever asshole gets in doesn't decide to start cutting the NIH, I'll have to go home then! (I could totally see Trump saying NIH money shouldn't go to train foreign students, and he'd probably be right too)