I just got off the phone with ATT and was told that, since I was adding a line and swapping the main to the iPhone 4, I could go into the store ahead of the iPhone launch and get a micro-SIM with my current phones info on it. Was told that the micro-SIMs used for iPad are the reason why. So just walk-in the store and ask to get a micro-SIM with your current account info on it and swap out on Thursday! I'm still waiting until I actually do it (tomorrow) before I accept it, phone reps aren't notoriously known for being right.....