With the announcement of iOS to be coming this Autumn and Apple have revealed a lot of the features to the world, but there has been a lot of disappointment from those who may have older iOS devices such as the iPhone 3GS, iPad (first generation).
When Apple announced iOS 6, they claimed that it would be compatible with older devices as far back as the iPhone 3GS, which was released three years ago in June of 2009. But as Apple have released more information about the new features on their website, people have become disappointed because a lot of the main features of iOS 6 will not be compatible with the iPhone 3GS or the first generation iPad. In fact unless you have the new devices such as the New iPad and the iPhone 4s, you won’t get all of the features of iOS 6.
As you can see features like the Offline Reading List and the VIP list won’t work on the iPhone 3GS. From what I’ve been able to gather the only real change for the 3GS would be that it received all the User Interface change for the apps, Cloud tabs in Safari and Facebook Integration, which is only a handful of features compared to Apples newer iOS devices.