If this happens its a good outcome.
Even better if there is some code checking or a requirement for open code for Apple(?) to make sure there are no major performance issues or privacy concerns.
First, it would be completely impractical for Apple to check all apps. There is no complete solution for automated code checking, so to do this, Apple would need to have someone manually read through pretty much the entire source of every app developed for the iPhone.
Second, why should Apple care if a third party app has performance issues. It is quite clear from the built in apps that the iPhone performs quite well, so I doubt users would be likely to blame a third party app's bad performance on the iPhone itself.
Third, there is a much easier solution to privacy concerns. Simply have the OS ask the user the first time an app requests any personal information from the iPhone for its own use, and then sign the app giving it permission in the future (if the user requests). The way the APIs are designed, an app does not even need to be given access to the content of, for instance, a contact record to be able to display and use the information. The app simply handles a generic record while the OS handles the data it contains. Thus, an app would rarely, if ever, need to request this permission of the user, and the user would be free to deny it if they did not completely trust the app.
I would certainly expect Apple to check all these things for anything sold through the iTunes store, but I believe it is completely unnecessary to do so for third party apps. (Maybe this could be provided as an extra service for developers for a fee, but otherwise I don't see this kind of checking happening for any apps outside the control of the iTunes store.)