It's time to "show me the code" :)
Please come back when you have a tree with the work you've done and would
like people to look at and contribute to.
Well, you ask for it :-)
I used to be a Misterhouse user three years ago and I liked the concepts and features very much. But I also had problems with the unstructured code base and it felt awkward to build my home automation for the next decades on code that did not seem to be maintained any more (see http://kaikreuzer.blogspot.de/2009/11/reinventing-wheel.html).
So I decided to do my personal "Misterhouse 2.0" on a modern software stack (sorry, but I am a Java/OSGi guy) and called it openHAB (open Home Automation Bus). I have just released version 1.0 a few days ago, seehttp://kaikreuzer.blogspot.de/2012/08/openhab-1.html
And yes, right here is the code that you have asked for: http://code.google.com/p/openhab/source/browse/
I am aware that this might not (yet) be an option for all of you who use X10 or Insteon - over here in Europe the prefered protocol is KNX, so openHAB has its strength on this. But it should be easy to also add support for X10 and Insteon as the architecture is designed for this extensibility.
So it is not a "refactoring of Misterhouse", which would mean preserving all functionality. But for everybody who starts new or who does not need certain Misterhouse features, openHAB might be a worthwhile option to consider.