1. Holding the botton for Siri if they launch it on the Ipad 3. 2. No way of doing a hard reset. 3. No way to use multi tasking with IOS5. 4. They would have to add more menus to exit apps. 5. The button is as Apple as the slide to unlock feature. 6. No way to get a screen grab if they remove it as you need to hold power and the button. 7. The home button is used for switching from page to page in the app/menu. 8. It would break away from tradition of any other IOS device. 9. On the first page if you press it then it will bring the keyboard up. 10. You can press it to get the light back on to unlock. Probably loads more reasons.