When I was an undergraduate I was taught that modern cosmology was founded upon the cosmological principle. This is the assumption that the Earth does not occupy a privileged position in the universe or, more generally, there are no privileged positions in the universe. In other words, the universe will look pretty much the same wherever an observer might be located (not so much in terms of physical structures but certainly in terms of the effects of physical laws).
However, a couple of researchers at the Institute of Theoretical Physics in Beijing have recently posted a paper entitled ‘Direction Dependence of the Deceleration Parameter’ to arXiv (here). The universe is not just expanding but that expansion is accelerating. In it this paper, the authors argue (based on their analysis of Type 1 supernovae) that there is a preferred axis to that acceleration.
If it its true it certainly puts a cat among the cosmological pigeons!