We do know the AppleWatch does have Bluetooth and NFC connectivity. We also know, that neighter Bluetooth nor NFC has a fast transferrate. It's enough to stream audio, exchange some informations, but not enough to transfer a bigger file. Apple must have some mechanism to update the Apple Watch. Tim also said the watch has some internal storage for music streaming. During the conference, he also said there are no exposed contacts. So, transfering files will be veeeery slow?