As you might have expected, Apple wasn't going to leave something as well-orchestrated as the iPhone 3G S launch to the whims of a mere courier. Despite news over the past few days that pre-orders of the speedy smartphone have been shipped, buyers are now reporting that their packages have been frozen with UPS, presumably to be released for delivery on the official Friday release.
Unlike the iPhone 3G, which had to be activated in either an Apple or AT&T store, the iPhone 3G S can be activated at home through iTunes. That allowed many people to preorder their new handset online, rather than face queuing on Friday morning when stores begin to sell the iPhone 3G S.
There's discussion now of whether buyers can physically go down to their local UPS depot and collect the package, or whether the courier will not release it until they've had confirmation from Apple. It seems likely that the latter is the case, unless you can sweet-talk/bribe/blackmail your local branch.