Neji didn't die. His seal was still on his forehead. That seal can only be taken out, by death. That means Neji is still alive.
This seems to be stated alot here about the seal still being on Neji's forehead. But going back to the manga, the seal was on his forehead while he was still standing. The last we saw of him was when he fell to the ground and the bird's feather landed in his hand. However, he fell face down so after he fell we didn't see his face or his forehead. There is no way for us to know if the seal was still on his head or not.
I am inclined to agree with Pervert-sennin about the bird symbolizing the freedom from the seal through death.

I like Neji and would like to see him live. But at the same time, it would be rather rediculous if he did live after the wounds he had sustained. It would be another typical "good-guys don't die" type of thing, which has been done to death. One of the things that I love about the Naruto series is that they do develope characters and then kill them off. It keeps the story fresh and always interesting.

I couldn't care less about Chouji though.