The new demo is not likely to ever come out for Mac as a demo. Ambrosia's policy has been to preview a game with the first couple of levels, then make people pay to get the rest. The demo, as a demo, does not really gel with that philosophy.
As to the new control system, that is part of patch 1.3. Version 1.3 for Darwinia has been out for Windows for a while now, and has been out for Linux for a couple of weeks. Testing has not yet begun for the Mac OS X version, and I have not gotten any response on the IV boards when I ask about testing and/or release dates. Suffice to say, it will probably be a while (a couple of weeks of testing after the patch is announced).
This brings me to my final point. Once the new patch is out, I anticipate that the level files for the new demo will be released as a mod to Darwinia, either by IV, or one of the enterprising members of the community. Thus, when the 1.3 patch finally comes to Mac, it is probable that the demo will come as well. The catch is that you will have to finish the game first.
I should also note that all of the above is rank speculation, and I could be totally off base, though I kind of doubt it.
xander
EDIT: rant != rank
This post has been edited by darwinian : 14 November 2005 - 10:02 AM