I'll throw in my .02...
I have no idea what the fuss over MobileNotifier is.
-I like the popup on the top of the screen to notify of a new alert, but MN doesn't go away after a few seconds. You have to do something with it, whereas in the iOS 5 beta it goes away after a few seconds and stores it in Notification Center. Obviously much better.
-The lockscreen implementation of MobileNotifier would be nice if you hadn't used any other program, but you can't open an app from there or even do a quick reply for SMS. So it's just ugly and unhelpful to me.
I think Notification Center is phenomenal. It works great, ability to add widgets (at least with a JB device), it looks fantastic... Notifications show up on the top for a few seconds then disappear... Apple got it right here.
The only thing I can think of is that they want Hajas to help with a QuickReply. Not sure what else he can bring to the table.
And I'll also note, biteSMS' QuickReply functions even better than MNs. So once again, don't know why he is now employed by Apple.
ANYWAYS... after downgrading from the iOS 5 beta, I'm really missing Notification Center. And after trying the likes of LockInfo and MN, I am back to trusty Notified Pro to handle my Notifications. I have LockInfo on the LockScreen, but Notified Pro for my infoshade.
Notified Pro isn't perfect and the lack of support from the dev is a bummer, but it is easily the best option we have for iOS 4.x.