Hillary began her (somewhat premature) Indiana "victory" speech on an up note, throwing an old Obama quote about how Indiana would be a PA/NC/IN tiebreaker back in his face. But since then she's sounded a little dispirited to me. When she delivered a line about the primary race is "so close," her heart really didn't seem in it to me--it reminded me of her weak delivery of that "change you can Xerox" debate line she seemed embarassed to utter. And talking about the future contests in West Virginia and Kentucy, she sounded very rote as she read from a script. It sounded more like she was talking about a trip to the dentist's office.
I may be imagining all this, it's easy to project based on what you suspect is happening. But Ben Smith notices something similar.
Update: David Gergen saw something else that I didn't: "It looked as if Chelsea's heart was breaking... She almost seemed near tears a few times." (But scanning back through the speech on Tivo I really don't see it.)