Christina Miller is stepping down as president of Cartoon Network, Adult Swim, and Boomerang.

In a surprise announcement, Christina Miller announced today that she is stepping down as president of Cartoon Network, Adult Swim, and Boomerang. She had held the position for five years.

Here is what we know about the situation:

Miller's letter to CN employees reads:

I would like to share some personal news. After much deliberation and contemplation, I have made the difficult decision to leave the company at the end of this year. This is not a decision I made lightly, and it is one of the most difficult decisions I have had to make in my career. Ultimately, I feel it is the right time for me to leave the company and take a little time to think about what comes next, but I feel great pride in the work we have done together and am very grateful for this experience.

I joined the company over 14 years ago with the prospect of working on some of the most iconic brands in the world. But what has kept me here all these years has been the wonderful, talented, all-around great group of people I have had the pleasure of working with. Laughing, grinding, and executing big ideas in all of our ventures is what has set us apart, and the talent contained within the organization is truly awe-inspiring. Each and every day I have been motivated, challenged, educated, entertained, and enriched by each and every one of you.

What I remember most about this experience are the countless opportunities that have been given to me, the support I received when an idea that seemed outlandish at the time ultimately changed our business, and the trust that was placed in me every step of the way. I am immeasurably grateful to the entire executive leadership team, past and present, who invested in me and allowed me to manage my career path in ways I never could have anticipated. It was an experience I will never forget in my lifetime. I leave feeling incredibly fortunate to have been able to call it my "job" for so long.

This is an exciting time for Warner Media and the beginning of a new chapter for the company. You have all been waiting incredibly patiently for the next phase to begin, and that time is approaching. While I am not leaving yet - I will be working with interim leadership until the end of the year - when I do leave, I will not only be watching from afar, but I will be cheering you on from every seat in the house.

So this is not really a goodbye. Instead, consider it a heartfelt thank you for this experience and a toast to the future for all of us.