Declining vs. simply not answering a call are different things. The idea with a notification type of approach is that things aren't obstructed by it and don't block you from doing something and you can just dismiss the notification without actually taking any action on the call (answering or declining it).I must be missing something here, but why has these been 'much desired'?
When a phone call comes in you want to see quickly who it is, and either accept or deny the call. At that point this is the SOLE purpose of the phone. Until you accept or decline you can't do anything else anyway, so what exactly is the advantage of making it smaller and more 'unobtrusive'?!