That's only an option if it's a separate iPad app. I guess a lot (most?) iPad apps, especially just after launch, will be existing iPhone apps with some UI twea

That's only an option if it's a separate iPad app. I guess a lot (most?) iPad apps, especially just after launch, will be existing iPhone apps with some UI tweaks. You can't take an update offline in the appstore without completely removing your app (you can only have one version).