Somewhere along the way, I believe Dr. Dawkins admitted that he thought the fine-tuned universe argument was the most compelling theistic argument he had encountered. I don't know if that's Dawkins's catty way of saying theists have no good arguments, but I think the idea is rubbish.
From wiki: "The fine-tuned Universe is the idea that conditions that allow life in the Universe can only occur with the tightly restricted values of the universal physical constants," which therefore implies an intelligent fine-tuner (I've added this last bit here).
First off, I think it is abundantly clear that the Universe is not fine-tuned to allow life. How much life do you think there is out there in the vastness of space? Sure, there might be countless alien worlds teeming with life. Even so, consider their place in the vast, vast, inhospitable coldness of space. The Universe is not fine-tuned for life, it's "find-tuned" to be a vacuum filled with violent cataclysms and mostly lifeless arrangements of matter.
In trying to visualize life and Earth's physical scale in the cosmos, consider an analogy from the crank pseudo-science known as homeopathy. Practitioners of this new-age nonsense believe that a 1ml solution diluted in water or alcohol the size of a cube 106 lightyears by 106 lightyears by 106 lightyears has special healing powers. It doesn't have healing powers. In fact, the original solution is effectively non-existent after so much dilution.
And that's like us folks. It's kind of ego-deflating, I know, but suck it up. That's life's place in the Universe.
Furthermore, the notion that our "fine-tuned" situation implies an intelligent fine-tuner does not follow. I posit another analogy, this time from that wonderful game show the Price is Right. Now, when I was little, I really wanted --heck, I still really want to play the game Plinko.
In this game, contestants drop disks into a grid of prongs, which then, according to the laws of physics and probability, randomly bump around until they land in either the one winner box or one of several loser boxes. Consider the winning box the existence of life and consider the several losing boxes a non-life state.
Sometimes a disk falls in the winner box. If that disk could think, it might look back on the path it took and say "Gee, look how fine-tuned my existence is! There were so many other possibilities, but here I am. There must be a mind behind this." But that thinking disk is actually ignoring all the other possibility states, isn't he? Matter or energy emerge and self-organize all the time, but they rarely produce life. Life isn't special, it's just lucky. And I mean no offense to the contestant, but his or her involvement in this process does not equate to mindful, intelligent will. The contestant has no idea where that plinko disk is going to land after he or she releases it!
Life won the luck of the draw and that's it. improbability does not equate to impossibility. This Universe is not fine-tuned for life, and even if it was, even if life was everywhere, it would not imply an intelligent tuner.