There is a big problem with having the screen go all the way to the edge! Protective cases have to wrap over the top a little to securely hold the phone.
This silicone case (speck brand) on my 3GS wraps over the top a little bit but it gets in the way of typing quite often. It can be pretty annoying. But it's a small trade off for the protection. My BFF dropped my first iPhone, it was in a hard plastic case that popped apart on impact and the screen was destroyed and the phone ruined. I had to replace it out of my pocket.
I ~swear by~ these speck silicone cases. Many times I have dropped my old iPhone in a case just like this one and dropped this phone in this case, one time I dropped my 3GS from 8 feet up and it landed on cement. It was totally undamaged.
Anyone that doesn't use a protective case is a fool. These things are fragile and expensive. I will not use a smartphone without a drop proof case.
If they run the screen to the extreme edge they are going to make it very difficult to protect the phone properly.
All the way to the edge is a BAD idea. I hope they are never that stupid to make one like that.