No, I am not referring to the fact that we can expect the Apple and ATT systems to crash again under the strain of day one activation. So you receive your new Iphone 4 with its new Micro SIM and you have your old phone with your number on the SIM that does not fit in the new Iphone. How will ATT deal with this. Will they set up the new SIM with your existing number so that now you have two SIMS with the same number. Probably unlikely. Will they ship the new SIM with a new number and require you to visit an ATT store to swop numbers. Workable but inconvenient. Will they provide a new APP that allows you to swop your number to the new SIM. Perhaps a Security issue. Or perhaps they will just provide you with a pair of Scissor to cut down the old SIM.