As the iPhone is notorisly known for breakage for even minor drops (especially the iPhone 4 and iPod 4) I would most certainly hope Apple is looking for a"better" glass source if they want to keep the full glass face on those phones,iPods, and the iPad. the very fact Apple can be talked into replacing the breakage for free ( not known to everyone) tells me Apple is fully aware of that problem.
Protection needs to be at the edges of the glass (full coverage of the bezel) that will protect it from a fall full faced or a corner drop.
I have never had a scratch on my old iPods and nanos glass, but cheaper off brand phones get scratched up bouncing around in my tractor or pocket without a screen guard. Incidentally those cheaper cellphones have never had the glass broken after some pretty disastrous accidents because they never had the beautiful full glass face of the iPhone and iPad. I was told they had gorilla glass on them from the cellphone company.
My iPad4 has a great cover but nothing on the glass,