We see some Michonne action right off the bat using her katana to kill some zombies in a store. We also see the Governor in the town of Woodbury, Michonne asking for their weapons, and laying the foreshadowing that the Governor is evil by Michonne uttering the words, "I don't trust him."
And the clincher is seeing Merle with a knife wrapped to the stump of his right hand.
If you have the time, please watch the video. It's great.