Someone asked me why I thought that AFR supported theism. My response.
Although I mention the Wikipedia argument on my site, it's not exactly my argument. What the argument from reason shows is that the fundamental causes of the universe are mental as opposed to non-mental. This is something that It doesn't get you theism per se, and when C. S. Lewis himself accepted it, he turned, not to theism but to Absolute Idealism. In Surprised by Joy, and in Miracles chapter 11, Lewis provides independent reasons for rejecting the Absolute Idealist or the Pantheist position. He does not simply regurgitate the argument from reason.
I also emphasize this in my essay for the Blackwell Companion to Natural Theology.
At the same time, if successful, it supports theism in that one it shows that one feature of a theistic world-view, namely that the source of all reality is mental and not physical, is true, and that the most popular alternative to theism, scientific naturalism, is inconsistent with the very possibility of science. I think if that can be pulled off, it's a good days' work for a philosopher.