For iPad, there will be new version of it maybe in the early quarter of next year since Apple will put it in competition over RIM's Playbook. For Macbook Pro and Macbook air, all of them have been updated few months ago and of course we've seen Macbook air few days ago. for iMac, I also heard Apple ...

@jbarnes : it's a normal problem because some of the apps haven't been updated yet with iOS 4.0 compatibility. The problem will solved if there is an update for the app. So don't worry. I'm having it too
@Turboladdade: yeah, it's happening with some apps but some still working..