iTunes 10.5 Beta 4 for Mac and Windows Released for Developers

As you all know just a few hours ago, Apple just released the fourth pre-release version of iOS 5. As with all beta builds, iOS 5 beta 4 is only seeded for those who have enrolled an account in Apple's iOS Dev Center. The smaller release timeframe between beta 3 and beta 4 indicates that this pre-release version offers performance and stability enhancements as well as numerous bug fixes. Although, iOS 5 beta 4 does come with a new feature, it is the first ever iOS that supports Over-The-Air (OTA) updates. Alongside the release of iOS 5 beta 4, Apple also pushed out iTunes 10.5 Beta 4.

If you are planning to upgrade to iOS 5 Beta 4, then it is strongly suggested that you download iTunes 10.5 Beta 4 since it is a major requirement. Most especially if you are upgrading to beta 4 without the aid of OTA updates.

You have to keep in mind that in this iTunes update will only work with iOS 5 beta 4, so if you are in iOS 5 beta 3 and below, do not install iTunes 10.5 beta 4. If you do, you may find that iTunes may return an error that your current firmware is not compatible. Anyway here's the full release notes of iTunes 10.5 beta 4 for your convenience:
If you are still under iOS 5 beta 3 and below, then it is highly recommended that you upgrade to beta 4 right away. There is simply no point in staying with an older firmware especially when there's already an improved version of it. Unless of course you have jailbroken your device to iOS 5 beta 3 and below or you've installed iOS 5 without a developer's account, then we don't suggest you upgrade to beta 4 because Apple will have no doubt patched all the vulnerabilities with this update.

If you have a developer's account, just head over to Apple's Developer Center and download iOS 5 beta 4 together with iTunes 10.5 beta 4.