For Z-Wave: the current integration is based on openzwave, a reverse engineered implementation of the Z-Wave protocol with an irregular release interval. As we depend on their releases, it's out of our control.
However, there is hope :) Sillicon Labs (owner Z-Wave) has recently published an official SDK for Z-Wave[2]. Once Home Assistant Cloud is generating money, the plan is to pay a developer to integrate it into Home Assistant. Once we're on an official stack, I expect our Z-Wave story to improve significantly.
[1]: https://www.youtube.com/watch?v=_qpKe-FW9Yk [2]: http://zwavepublic.com/developer