This is certainly interesting to know about and I've bookmarked it for
future reference.
My interest comes via the philosophy of physics, and in particular the
simulation arguments that have been fashionable recently, with
otherwise sane people such as Frank J. Tipler putting forward scenarios
that have no real value outside the centre pages of New Scientist. I
presented a paper to the ESSSAT Conference in Barcelona in 2005,
proposing a reductio ad absurdum of simulation arguments in general -
it's at
http://www.nugae.com/philosophy/simulate.pdf (I cannot see a
suitable arxiv.org category for philosophy of physics).
In this context it is valuable to get away from the question "can we
simulate the exact laws of the existing universe?", since this is
simply a distraction. Having a cellular automaton that can potentially
exhibit sufficiently complex behaviour to have its own "thermodynamics"
and eventually its own "biology" clarifies the philosophical arguments;
on the other hand, if it turned out that no cellular automaton could
generate sufficient complexity then that would itself be a very
interesting result.