We're sure the first thing you'll want to do when you get that new iPad home is give the 2048 x 1536 Retina Display a workout. With that in mind, Apple has curated a section of the App Store especially for apps that have been updated with full high resolution support, like Infinity Blade II. Here are a few of the more notable inclusions; we'll be adding to this list as more updates come in.
Note: it appears that not all the apps in Apple's "Great apps for the new iPad" section actually have Retina Display support — for example, the US App Store lists Gameloft's Modern Combat 3, which is yet to be updated as far as we know. Similarly, you should expect a lot of apps with Retina Display support not to make it into the curated section.