Yes! We have just released the Public API for Todo.ly. You can use it right away.
There is a Wiki page for every detail: http://todo.ly/ApiWiki/

In nutshell, the API is very simple and powerful. It’s entirely HTTP-based RESTful API, and follows the same structure as the Twitter API. It uses HTTPS Secure Connection.

The main Object Structure:

We have a C# Library for the API already, that we will put on the Wiki page in a few days. If you want to implement a Library in other programming language we would be more than happy to publish that on the Wiki page.

Of course if you have any comments, feedbacks you know how to reach us.