I wasted 10$ on the screen protectors that I got from Verizon when I picked up the GN. I would clean the damn phone for 2 minutes with the cloth and every time there would still be a piece of dust that got on the screen and just ruined it. I also felt like the screen protector ruined picture of the phone. I'm leaving it completely naked, even when I do get a case I still won't put a screen protector on the phone.
My advice is to try out the BoxWave ClearTouch Crystal screen protector when it comes out on the 22nd, if you are really worried about scratches. Or you can just be very cautious