This is an area of considerable interest as I also have not read of much success in neuron regeneration. From Georgejjl's post it seems his primary hypothesis is that the MOA for super responders is through improved capability of the remaining brain tissue (my interpretation of homeostasis), which if through improved connectivity could mean neuron regeneration or "revitalization" of some existing neurons. If this were the case that would be a very exciting development.
Even "stopping" disease progression, thus having some showing cognitive improvement in 18 months by statistical change would be an important breakthrough, as by providing treatment early in the disease quality of life would be significantly extended. I look forward to further discussion on this topic, and also of course to further information from Anavex.