Yeah, this is the most concerning thing. I know I know, anecdotes and all that, but from my observation the language being aimed at Hillary from the Sanders camp is unlike anything I remember seeing between Hillary and Obama's campaigns in 2008 in how vicious it is. The most you really see from Clinton supporters is concerns about Bernie promising things he couldn't possibly deliver and being a bit naive, but most people that I know generally like the guy and I think a lot of the party generally agrees with Bernie's destination even if we seriously disagree with the way to get there. But the attacks on Hillary from his supporters range from disliking her policies to pissing on her as a person. It's terrible, and as bad as any Republican onslaught.
Going forward, I'd definitely like to see Bernie keep fighting (because he HAS made Hillary a stronger candidate), but as the writing becomes a bit more clearer on the wall I hope he changes his language to discourage some of the vitriol being stirred up among his supporters.