IMO As long as you keep letting people assign a score to reviews that will encourage "some" people to do padding reviews or fanboys. I think it would be much better to get rid of the numbers, get rid of the top 20 lists and let the actual reviews stand for themselves.
I don't think the average person is the problem (or even the "fanboy"). I've looked over the average ratings of reviewers, and most range in the 3s, if they've done more than a few reviews. It's only the d20 Magazine Racks people that always give good ratings. They're the problem, IMHO.
They say they have all these guidelines, but in practice, it almost always results in a 4 when translated over here...
Which is also why I think splitting up the d20 Magazine racks into individual reviewers is pointless, because the net result is they all give 4s.
Personally, I think their reviews should be dumped, and simply post a link to the d20 Magazine reviews site, because the way it works now doesn't really benefit anyone. The poor way their scores translate over makes the d20 Magazine people look bad (unfairly), it gives d20 buyers the wrong impression, and it reflects badly on ENworld, giving it even more of a reputation as fanboy central.
Really, I think what's needed here is getting more average gamers to write reviews, by giving them an incentive. Maybe have a contest for people who write reviews - winner gets a free Natural d20 PDF (also would give you more reviews of those products, which presumably help sell more of them...)