Gentlemen and ladies, start your iTunes. Just not yet. The new 3.0 OS update for all existing iPhones is scheduled to come out today, but it hasn't arrived in iTunes as of 10 AM ET. According to general Web scuttlebutt, the update will arrive around 1 PM ET. Expect Apple's servers to be slammed, so if you can possible wait until tomorrow, do so. Friday will be another bad day for Apple's servers, because of the arrival of all those new iPhone 3G Ses. To download iPhone 3.0, connect your iPhone