I pre-ordered a book from Amazon.com like 2 months before it was supposed to come out for my son, and we thought that meant that the book would be shipped to us so that he had it on the day it was released, well it wasn't. It was shipped on that date so he got his book like 4 days after it came out, and he wasn't happy about it, everyone else in school had the book before him.
My point is that if you want something on the day it is released I wouldn't order it from Amazon again.
Amazon guarantees release date delivery on video games. I have not had a problem.