We posted a short while ago that iPad apps are now in the App Store. An interesting feature we just discovered is that iTunes now splits your downloaded apps in the Apps library in the iTunes source list. Any iPhone app specifically optimized for the iPad is now segregated into its own category. In your iTunes App library you'll now see two headings: the top heading is "iPhone, iPod touch, and iPad Apps" with all the non-iPad optimized apps relegated to an "iPhone and iPod touch Apps" category.
An iPad-optimized app is an iPhone app that supports both the iPhone's and iPad's native resolution and thus doesn't need to use the iPad's 2x zoom feature to display the app full screen on the iPad. And while we haven't gotten a chance to sync up an iPad yet, we'll presume that iPad-only apps will have their own section as well.
Update: Apple is now featuring iPad apps on the App Store homepage in iTunes. Looks like the iPad App Store is officially live. Get those iPad apps while they're hot.