It was to give Voldemort something to do while Harry was getting ready, to give something to philosophise about (the apparently most powerful one being the worst/most trouble) and to provide a twist for Harry to unman Voldemort at the end.
I liked how JK ended the Story, although I think that the '19 years later' stuff was not neccessary. I mean, why does he call his kids like dead people who were mostly being murdered/ intended to be killed? Harry is a maniac, I always knew that
I like that she is killing a lot of people (that sounds weird ) because it's war and people die in war. But Tonks was unneccessary to kill *sniff* and Lupin too... Ok, I admit, I liked them and that Harry had this one last connection to his father's life...
I just finished it last night. Great book. Although, I do have to agree with some of the characters being killed off during the battle. I guess JK saw it fit though. I agree with the whole 19 years later. It was nice to see what happened even though most of us knew what was going to happen, would soon happen.
I actually really like the deaths in the novel. So much was completed in my mind and Rowling just ended the series with a BANG! I must say that i cried about five times in the whole book and Dobby dying made me bawl but books that can make one laugh and cry are books worth reading.
J.K Rowling could not have ended the series any other way and i am still depressed that it is done, i must admit that i am on my fifth time reading HArry Potter and the DEathly Hallows and i'm still enjoying every moment this book brings to me.