There's been no press release on how Dawn's recent flyby of Mars went, so finally I inquired at JPL for an update. Marc Rayman provided the following: "The gravity assist went perfectly. We will have the final navigation reconstruction near the end of this week, but the preliminary results show that the spacecraft's trajectory was extremely close to our predictions. Now it is great to have Mars behind us and Vesta now ever more clearly ahead."
Marc's usual Dawn Journal is due in only a few days, so we should have lots more detail shortly.