With only 2 fights in the UFC (one split and one close decision), it's too soon for Holm's title shot, but apparently she was prepared to fight Rousey after the Tate III rematch.
I haven't seen anything from Holm that convinces me she's the type of counter puncher who can knock out someone with Rousey's chin as she moves to clinch. Holm's strongest coming forward aggressively, leading with the hands and typically finishing combos with a high kick. Backing up, she's not nearly as dangerous. Despite her professional boxer roots, she has really taken to a kick boxer style with a fair amount of knees and elbows thrown into the mix, but again most of this is best displayed as the aggressor.
Her take down defense is largely untested, which is key if she plans on playing to her best shot at winning.
The perfunctory prediction is a round one submission via arm bar. Holm won't rush Rousey since she'll be weary of the take down and Rousey isn't going to blitz Holm so this one stands a good chance of extending beyond the first minute.
Tate is getting Nunes, which is no consolation prize, but a strong performance strengthens her cause for another rematch. Given that she was supposed to get this rematch after winning her last fight, one can't help but consider this to be unfair, but... the UFC is simply going with what they can most easily promote rather than giving any fighters who aren't box office draws their due.