An update for the Google Earth app has been released in the App Store, which finally comes as a universal application with native iPad support. It’s available for free here as a 12MB download.
The iPad version has full-resolution imagery and it uses native iPad popover menus to let you access the settings and layers. A road layer has indeed been added to the iPhone 3GS and the iPad. The app it’s the same Google Earth you’ve got used to, and it looks good on the iPad now. It’s available for free, check out the screenshots below.