If you bring your broken black iPhone 4 to the Apple Store, you might get a fresh iPhone 4S as your replacement phone. What?! Yep, because of supply constraints, many Apple Stores don't have any black iPhone 4 units (16GB/32GB) in stock so they have been instructed by Apple to give customers an iPhone 4S instead.
That means if you have a phone that's broken right now, you can get all the upgrades that the iPhone 4S offers—Siri, A5, better camera—for free! What a timely break. This actually happened a few weeks ago with the white iPhone 4 16GB (GSM) where Apple was giving users with a broken iPhone 4, a new (er, probably refurbished) iPhone 4S. The constraints with the white iPhone 4 has been resolved now and you can expect the problems with the black iPhone to fix itself in a few weeks too.
Scoring an iPhone 4S all depends on the stock of your Apple Store, of course, but if your iPhone 4 breaks today, just know you might be getting a better phone as a replacement. Let us know if you luck out with a free upgrade. [9to5Mac]