I did this to my ipad on the first day of my holiday. Bits of glass were coming off on your finger when you used it and it looked terrible. Apple said they did not replace screens, but i could replace the ipad. I took it to a local bloke and he fixed it for £50.
It's not quite as good as new, but i think that's cos the case was also slightly dented, so he had to misalign the screen slightly. It still works the same.