I thought it was really sad how Snape basically gave up his ENTIRE LIFE so he could be a spy and try to protect Harry and everyone else...and then he died. It was really sad. Regardless of his creepy, greasy exterior, through his actions that came out in this book, he was probably the bravest and most honorable character of them all, and I didn't like that he just died alone without anyone.
I can see the major problems it would have presented for JK Rowling if he *had* lived though, for her, it was easier to have him die!