If you look at the layouts, there's a sun above Tim-fighting-Steph's head for one of 'em. And one of the DC boarders said he had up a color cover (which he took down) where the Red Robin half of the cover was at night, and Tim-fighting-Steph was in the daylight. So I'd say Tim is still Red Robin, and this cover is a Tim-at-day and Tim-at-night sorta thing.
As for Steph, I'm glad she's appearing somewhere, but rolling my eyes at those two being even bitchier too each other. At least Steph appears to be putting up a good fight, blocking Tim's punch. I hope Yost doesn't humiliate or degrade her.