To the originator of this topic, I would say, unless you yourself are planning on making a metal album where drums are not used, then just put this entire idea on the shelf for the moment. What I have learned from all the metal coming out in the last few years is that there is nothing wrong with the instrumentation or even styles of playing in metal, but rather that no one had anything interesting to say with it. No one had any spirit in their music or inspiration. It was just a massive game of stupid cross-overs. For a while, because of these defects, I believed maybe a new genre of metal needed to to be created or a new way of making metal.
But then with all the better albums that have come out lately, I now know that the people who are making great music right now are just doing the same old things great metal bands always did, in instrumentation, playing styles and even lyrical imagery. The missing component was spirit and quality and not origininality. Substance before form, as is the popular saying around here. These thoughts that I am relating are not original and you are probably seeing a lot of this kind of talk lately.