1. iCloud integration
For Apple this is the major, new feature of iOS 5. Your iPhone, once it runs iOS 5, will have several new features in relation to the iCloud. For the uninitiated, iCloud is Apple's latest innovative cloud service. With iCloud integrated on your iPhone, you can now sync contacts, calendar, reminders, bookmarks, notes, and stream photos to the iCloud server. iCloud then pushes these contents to your iPhone and other iOS devices wirelessly. This means that you'll have instant access to your music, apps, latest photos and more as well as keep your email, contacts, and calendars updated on all your iDevices.
When you sign up with iCloud, using your existing Apple ID tied up to your iPhone, you'll have up to 5GB of storage for free. You can always increase this by purchasing more storage capacity. The good thing about iCloud is that the music, apps, books and your photo stream, does not count against your free storage; leaving you more room for your camera roll, mail, documents, settings and app data.