According to Information Week, the redesign of the App Store that accompanied the release of iTunes 9 could have significant implications for developers, particularly those with apps in the long tail.
The new layout of the App Store focuses on creating a big, scrollable browsing area for each application category, but makes it difficult to figure out how to browse by genre subcategories. In fact it took us a few minutes to figure out how to view them -- you can get there by clicking the "browse" option from the iTunes Store home, but as far as we can tell you can't get there from within a category page (please let us know if there is a way).
Smaller developers and others with apps who were seeing success from being top-ranked within a subcategory are now by default lumped into a much larger category bucket and facing less visibility in the store. The fear is that sales will slump as a result, and preliminary reports from some developers indicate their daily sales figures have declined since iTunes 9's release.
The sentiment of some iPhone developers is that it seems like Apple is putting more support behind the larger, more established development houses and putting less focus on the small and independent dev houses. On the flip side, there's some hope that the addition of the Genius recommendation system to the App Store, once only applied to music, may help make up some of the lost visibility. There's also optimism that Apple may implement a better method of resurfacing those smaller apps that took a sudden dip in promotional opportunities at the store.