I was wondering the same thing...
I think that for web-connected apps it will flush out over time. We now have NY Times native app and AOL Radio. Some reviews say the web sites are better than these 1.0 native apps.
Having local storage capability is the key feature for native apps. I'm looking to rely on local storage for things like to-do lists, small database apps and news readers. These are things web apps just couldn't do. And of course, real gaming.
A few apps such as Last FM still are in reality web apps. There is nothing on Last FM that runs on the iPhone alone other than the icon.
probably not since it cost $99 to put your app on app store