I predict that eventually there will be only be single celled life on earth.
I don't particularly agree. No matter how the environment changes there will always be niches avaliable only to metazoan life.
It doesn't detract from your central point, but ToE doesn't predict diversity, it is formulated to explain it.
Fair enough. I was simply trying to get across the point that diversity, which is easily measured and recognized, is a far better metric of evolution's trend than fuzzy, ill-formed ideas about "complexity".