Not much of note emerged, although one does get the strong impression that Mrs. Obama is not a "happy warrior." And it's worth pointing out that she talked repeatedly of the "sacrifice" that his running for the presidency entailed for both her and Barack.
A little free advice: Best not to keep on implicitly soliciting the gratitude of the American people for your presence in the race. After all, everybody knows that Hillary Clinton doesn't consider any of this a sacrifice -- she lives for this stuff.
One of the smartest politicians I know (who's held a variety of high offices) once told me that it was important for candidates explicitly to ask for voters' votes. I think that's right; people want to feel as though they're bestowing something of value on a candidate by virtue of supporting him/her -- not that they're the (presumably grateful) recipients of a candidate's noblesse oblige and "sacrifice."