I don't think, myself, that complexity proves a Creator.
Complexity proves time (billions of years), and motivation (survival).
The human mind does not do well with time on a geological scale. Nor with complexity. The temptation is to think that if we find something beyond our comprehension (like compexity, infinity, time), then there must be a God to explain our lack of ability to get a brain around it <g>.
On the other hand as I've said before, a "2001- A Space Odyssy" -esque manipulation of life here on Earth is very plausible to me. Remember that obelisk at the beginning? That's not God, that's a meddling alien....
