Although this has nothing to do with categories, it should be of interest to all mathematicians. According to this: http://groups.google.com/group/sci.math.research/browse_thread/thread/43d737... someone is claiming proof of the abc conjecture by adapting somehow the valid proof for polynomial rings F[x] over a field that uses formal differentiation (this can be found, e.g. in Lang's Algebra). The abc conjecture easily implies the Fermat Last Theorem as well as a number of generalizations (such as the impossibility x^n + y^m = z^p with obvious exceptions) and more. It would be an astounding result. Michael