Might it not be useful to have a comment box in each Rack Extension page in the RE shop? This way, the rating the people give could be backed up by a comment, why a particular rating has been given. It might help the developer to easily see what is missing in his Rack Extension that could make it get a better rating and perhaps sales if he chose to look at implementing the requested feature(s).
Also it would free up time of the developer, because he/she would not have to scroll through countless pages in the forums to see what customers (or potential customers) would like to see implemented. Time that could be spent on improving the Rack Extension in question
I believe I remember something like this has had been suggested here before, so in this case I just would like to add to that