How will i phone apps look on pad. Will they just be in the center of the screen covering the same size as the phone unless you enlarge? And than if you enlarge they may be distorted, right?

You can run iPhone apps in normal mode in which case the app is centered on the screen with a big black border. Of you can double the size of the app with will fill the iPad screen for the most part. If you want an idea of what it will look like, take a screen grab of an iPhone app and then zoom your picture viewer to 200%.