This very recent result can be found in Peter Auer, Harald Burgsteiner and Wolfgang Maass "A learning rule for very simple universal approximators consisting of a single layer of perceptrons".
The initial excitement became somewhat reduced, though, when in 1969 Marvin Minsky and Seymour Papert published the book Perceptrons with mathematical proofs that elucidated some of the characteristics of the three-layer feed-forward perceptrons.