Given the state of useful information on home/lockscreens in competitors (Windows Phone 7, Android, WebOS), it's almost necessary for Apple to make a UI overhaul in iOS 5. I'm loathe to jailbreak (performance issues), but when I have jailbroken my phone, the lockscreen with usable info (weather, notifications) was brilliant. I don't think Apple should open up the lock/home screen to the app environment necessarily, but Apple should do something to make their devices more useful when they aren't in active use.