As pointed out at the end of the blog article, Disney/Pixar is well known for putting Easter eggs into its films that refer to past films and to future films, but I have never seen an Easter Egg that welded so many films together, nor one that was so well done. So, well done Jon for the blog article and Ed for posting the link to it.
Looking at the time line, excluding "Brave" everything begins in the 1950's on this alternate earth. I was born in the 1950's on this earth, which raises the question: "If it was all possible, would I like to be born on this earth, or born on the alternate earth?"
Knowing how everything plays out in the future, I think I might like, if I had the choice, to be born on the alternate earth.