According to Engadget, HBO Go is coming to the Xbox 360 on April 1st.
This is what Engadget said:
Tonight at an HBO event in San Francisco, company Co-President, Eric Kessler, gave us the good news that Microsoft’s console will be getting the streaming service on April 1st. It’ll make its debut alongside the premiere of season two of Game of Thrones, so you’ll finally be able to jump straight from the hills of Tamriel to the fields of Winterfell with the greatest of ease.
The Xbox 360’s TV and Movie line-up is growing – I wonder what will be added next?