From a striking perpective, in her most recent fight against Sarah Kaufman, for the brief moments the bout stayed upright, she showed an ability to close the distance with punches. In other words, we're guessing that her striking is continually improving, thought it's hard to know for sure.
What Liz Carmouche brings to the table: Carmouche is strong. She's a good striker. She's a decent grappler. And she's knocked four people out during her career. So there are skills. Carmouche is also a former Marine, so mental and physical toughness are in surplus.
That said, this is Rousey we're talking about as an opponent.
Ronda Rousey vs. Liz Carmouche Prediction: Carmouche asked for this fight, so we have to give her credit. But if Sarah Kaufman couldn't get her strikes off against Rousey, I doubt Carmouche will be able to. Expect Rousey to crowd her opponent early, take her down, and do what she does.
Ronda Rousey defeats Liz Carmouche by first round armbar.