Ahead of the Apple press conference tomorrow morning, an iOS4 update to version 4.0.1 has hit for iPhone 4s as well as an update for the iPad to iOS 3.2.1. There haven't been a ton of additions with the new iOS, but the promised change to the signal bars seemed to have happened as the before and after picture shows above. The iPad update seems to have fixed some WiFi issues and video playback errors.