iOS: Unity 4.0 discontinues support for ARMv6 devices (iPhone 1st gen, iPhone 3G, iPod Touch 1st/2nd gen). This affects existing project development in several ways:
Target Platform Player Setting was removed from Unity Editor. Now all Unity iOS applications are ARMv7-only. Corresponding PlayerSetting.iOS Editor API entries also were removed. You might need to fix some of your editor scripts for that.
Graphics API level (Open GL ES 1.1 or 2.x) selection was moved to separate Graphics Level Player Setting. This setting is synced with the Android platform.
Applications that were already released to the App Store as supporting ARMv6+ARMv7 or ARMv6-only now can be updated only if Target iOS Version Player Setting is set to “4.3” or higher.