I read on another forum that essay questions for Haas, Columiba and Harvard are already out! You can check their websites.
I would think most of the Schools will announce their Essays and app information by mid July (just a guess).
I am sure experts here will be able to give more accurate answer.
"To dream anything that you want to dream, that is the beauty of the human mind. To do anything that you want to do, that is the strength of the human will. To trust yourself, to test your limits, that is the courage to succeed."
- Bernard Edmonds