You can see screenshots of the horizontal card based interface here from the original Chomp app: http://itunes.apple.com/us/app/chomp/id348286549?mt=8
IMHO, the team at Chomp has too much power over the App Store. Apple comparatively few acquisitions per year so I wouldn't be surprised if the Chomp team totally took over App Store search.
As an indie developer I'm hoping someone at Apple is seeing the iOS 6 app download before and after results and isn't happy about the trends.
In the recent keynote, Apple CEO Tim Cook said that 90% of the over 700k apps in the App Store are downloaded every month. I don't see that happening anymore with the current state of the App Store.
I think that's the problem. It sounds crazy, but for most of us, the icon is actually one of the most important deciding factors... A shitty app (with horrible usability and UX) with a nice icon sells an order of magnitude more than a decent, pretty app (UX-wise) that couldn't afford a great designer for their icon.
This is (I think) the reasoning behind the change. How much have they succeeded? That's a whole other issue. But I think they aimed for the right thing.
The only reason I can think of behind Apple's decision is that they're trying to cater to big companies and studios, so that when you search American Airlines, you can be sure that that first result, and the only result shown, is the official app. That's great for big companies with a recognizable name and brand, but terrible for people trying to compete in the games/social/etc spaces, where the apps are often named "motorcycle racer X" and are competing against 20 other similar ones.
Edit: Much of these criticisms apply to the categorical app pages as well.