Senior Vice President of iPhone Software Scott Forstall has recently joined Twitter with a verified account, though if he's just protecting his name, he may want to make his Tweets private to prevent the public from using him as a lever for customer support. I imagine Forstall is doing just that: protecting his name on Twitter. He doesn't have a profile pic and hasn't tweeted anything, so until we see those crazy eyes, the account's just a placeholder.
However, TechCrunch speculates on the possibilities, mainly that Forstall is either interested in learning more about Twitter for a future iOS implementation. Though After Apple's incredible profile on Twitter, I imagine Cupertino already has some insight into the company's operations and software.
And don’t forget the rumors that Apple was thinking about Facebook integration for the iPhone. Nothing came of that with iOS 4, but integration of Facebook and Flickr in software such as iPhoto, suggests that Apple isn’t opposed to such partnerships. For the iPhone, Twitter could be a perfect one.
I can see the headlines now. "iPhone 5. 140 Characters Re-imagined." Or something magical like that.