iFixit Tears Down an iPhone 4S
The guys over at iFixit tore down the iPhone 4S already, identifying every component on the device. The frame and screen is virtually identical with the iPhone 4, with some minor physical changes, such as the volume buttons being slightly off from the AT&T & Verizon iPhone 4. The processor is very similar to the 1Ghz A5 found on the iPad 2, but will be running at a lower clock speed (800Mhz) and a lower voltage. The 4S also features the same amount of RAM as its predecessor, running 512MB of DDR2. One nice thing they've done is included a microSIM card slot on all of the iPhones, so with a bit of work, they can be used on all GSM networks. Unfortunately, as of now none of the providers will be selling unlocked phones.
Take a look at the complete teardown from iFixit: