Although the UPS tracking still shows that it is expected to be delivered tomorrow, it's not showing any tracking information yet other than "label created". I wonder when UPS will pick it up from Apple.
My 38 went through this last week - you will have it tomorrow.
Basically: late Weds night entered PFS; Thursday nothing - until late that evening, Apple sent a shipped email - but the tracking # showed nothing under UPS (called Apple, sent me a new text with a correct tracking #); Friday I received my watch.
It will come as its shipped via Next Day Air saver (before 3 pm to a business address, could be up to late evening if residential).