Currently Being ModeratedFeb 7, 2013 11:37 AM (in response to Terry P)
Don't know. But I've seen lot's of poor reviews of apps, so I highly doubt that any outright censorship of poor reviews is ongoing.
It's possible that reviews are mdoerated (eg, for profanity), which causes a delay in the publishing of the review. And I'm don't think reviews stay published if the version of the app cahnges (you have to specifically select an "all versions" view to see old reviews).
And finally, there is a difference between ratings and reviews. The summary graphs show ratings, but not everyone who rates an app leaves a review. It's quite common for there to be far more ratings than reviews, by an order of magnitude, in some cases.