In iOS 5 it was no problem, swipe across it and delete. In iOS 6, it does nothing. Is there a other way to hide some previously purchased apps in the App Store?
Solution (1/3/13): you can hide previously purchased apps via iTunes 11. Go to the iTunes Store, on the right side there should be a 'quick links' section with a "purchases" link; click that link, then go to apps sections, hover over the icon and click the x at the top corner of the app.