It is, partially (via the wxKeybinder plugin) and it will be (generally supported by the core application). Only just not now.
Although the action-based, fully customizable event system is practically ready for use, there is no way we could release it before version 1.0, as we did not have and do not have the time to thoroughly test it. You wouldn't want us to release code which we are not at least 99% certain of, would you.
If you look at the roadmap, you will see that we already have an almost unreasonably tight schedule. We will only have 1-2 weeks to test all the changes that we have planned for the final release before meeting release date. Actually, that is pure madness, but we don't have a choice, tempus fugit...