...I'm still not convinced that impermanence implies radical atheism. I keep returning to the possibility, which Hägglund simply doesn't consider, that there is a god, and that she is mortal, and that she created the Universe, or that she is the Universe. Such a god would exist as much as a pear or a floating iceberg exists—not that much, according to the deconstructive view, but existence nevertheless.
Inevitable self-promotion here, but this is precisely the position that I develop in Goddess as Nature. Most Goddess feminists and many Pagans, of the Starhawk, Z. Budapest variety, both view and value the Universe/Nature as a mortal, impermanent deity, who is also in some sense female, and whose existence is little different than that of the pear or iceberg that Tim deploys.
This Goddess as Nature and Pagan worldview is most readily characterised as a form of pantheism, a religious/philosophical position that atheists such as Dawkins rapidly dismiss as simply "sexed up atheism". It seems, though, as philosophers such as Michael Levine and Grace Jantzen have argued, that pantheism is an eminently defensible religious and metaphysical worldview that far, far too many simply reject in a knee-jerk fashion.
Quite amazing how many of these new and radical atheist arguments only play out as responses to an ontotheology that is shackled to the triad of Abrahamic monotheisms.
[Addendum: I should add that I am not aware if Hägglund claims or argues that radical atheism follows from impermananence (not being familiar with his work). I merely note that impermanence is assimilated into many theistic worldviews, and the degree of success probably warrants examination on a case by case basis.]