I'm watching the Keynote now for the first time, because I've been busy at work, and I just saw why there is the slits in the sides of the case, and thought I would post and share here because no one else has. The stainless steel casing is used as multiple antennas. The left side is for WiFi and Bluetooth and the right is for the network. I don't know how much it will help but I very much like the efforts they've seemed to go to to make reception better on this phone, but adding the glass casing and these two "hidden" antennas. I'm wondering if this has to do with the alarming rate that AT&T drops calls, or if Apple simply just wanted to make it better.