First and foremost, you want to figure out what happened and how to keep it from happening again. Now is the time to examine the snapshot you made of your system before you started the recovery process. When you've figured out what happened, you obviously want to take steps to keep it from happening again. You also need to think about anything you or others did during the response (for example, enabling or disabling certain software) that now needs to be undone, fixed, or documented and made permanent.
In addition to analyzing the incident, this is the time to analyze your response to the incident. In this phase, it's important to concentrate on critiquing the response, not on assigning blame for the original incident. Don't be confrontational but talk to any folks involved with, or affected by, the response. With them, try to determine what you did right, what you did wrong, what worked and didn't work, what other tools or resources would have helped, how to respond better next time, and what you've all learned from the experience.
If you made "incident in progress" notifications to various people and organizations, now is probably the time to tell them that the incident is over. Be sure to follow up with appropriate information about what happened, how you responded, and how you plan to keep it from happening again.