SPOILER :
I was talking with a girl I was working with and I came to these conclusions:Snape, Pettigrew and Lupin had to die, I didn't want them all to die (I liked Lupin and didn't see his death as being as important as the others) but they were the people closest to James and/or Lily. It was only right they went back to their friends. I'm a little pissed off Snape didn't walk into the woods with Harry, but otherwise it needed to happen.
Fred, Tonks, and Moony were soldiers in a war and soldiers die, senselessly, there's a lesson in their deaths no matter how much it sucks.
Hedwig was caught in the crossfire, her death was the most senseless but then her death was quite like the muggles that died for Death Eater's fun. In war the innocent are those who suffer most and saying a couple nameless muggles were killed by a supposed gas leak doesn't quite hit you the same way offing Hedwig does.
Personally JK Rowling went a bit overboard, but I respect her greatly for offing those characters, particularly Snape and Fred. Although unlike the rest of you if Snape didn't die I'd have condemned the book as absolute trash.