Here's a must read post on why Apple added Twitter into iOS 5. Apple really really thinks Mark Zuckerberg is a major (you fill in the blank but must be something negative).
With the rise of Google+ and the threat it possess, I wonder if Facebook will mellow out a bit and try to try to work with other companies like Apple. Yes, I did purposely write "try to try".
Google will stop at nothing to come after Facebook. And by working with another successful company with a strong mobile following like Apple, it provides an insurance policy of sort. Facebook will stumble and fall. At least by working with the likes of Apple, Facebook at least has some real friends.
Or at the very least, not make an enemy of a company that has a very vindictive CEO.
The implications of the previous Apple-Facebook over iTunes user data has left Apple's Ping without a link to the outside world. With Twitter, things will change for iOS mobile warriors.
There are also signs of thawing between the icy relationships between the two companies. On the online Apple stores, Apple appears to be experimenting with Facebook and Twitter updates.