The folks over at German developer HandyGames originally put together this slideshow presentation for their own internal use, but they determined that it actually could be useful for almost anyone following iPhone releases and their development, so they released it out into the world. And they were right -- there's some good info in here. Basically, they did a survey of the top 20 apps, both paid and free in five different regions of the world on the App Store, and then compared different qualities of all of those apps to see what the most successful apps had in common.
What did they find? Things like the fact that the majority of top 20 apps do not use all caps for the title and use an original IP for their releases. The differences are interesting as well: most paid apps are made by recognizable developers, while most free apps are made by smaller publishers. Free apps receive many, many more reviews than paid apps, though (if I'm reading the presentation right) they tend to be rated lower. Chillingo is the App Store's most prolific top developer, while Digital Chocolate releases games most often, with a full 1.5 releases per week since (I suppose) they started publishing games.
Very interesting stuff, though the numbers still require a little backgound knowledge to deciper (Backflip Studios appears in a few rankings, even though they've only just started releasing games last month -- popular games, but only a few games nonetheless). Cool to get an overall snapshot of the kinds of games that are doing well on the App Store so far.