Yes, it's 2.0.0, that's a promise of the API. No API breaks after 2.0.0 get released (It's already released today).
To tell the truth, I, Peter[1], and a few others take more than a month to think and discuss the API, even though there are just few functions to export. We try our best to make it better. In the end, I think, We are quite happy with what we get now: the unified API.
If a very good idea found to do the API, but the API would break, then it's version 3. But version 2 will still be maintained, and any bugs will get fixed. That's the promise.
