Won't traditional scoring and snapping work? Not sure what your application is, but why would the edges need to so clean. You can always use a shurform plane to clean up the edges afterwards.
If you must have really clean edges, I don't think the table saw is your best option. I have cut Wonderboard on a wet saw with good results--makes a nice clean cut with no mess. I have also cut it with my circular saw with an abrasive blade in it--it was really messy and there was lots of flying debris (sand/stones. etc.) I would not try that again. For this reason, I would not attempt on a table saw. Finally, a jig saw with a tile blade would probably work well with a lot less mess.