This news comes from the announcement of a day-one patch for the PlayStation 4, though it is unclear whether the patch is explicitly required to enable the features listed below. We do know, however, that "at first time use, users must connect to the internet" before Blu-ray and DVD playback will function, according to the press release.
Regardless, a launch-day PS4 will be capable of Remote Play through the PlayStation Vita, second screen experiences through PS Link and the PlayStation App on mobile, Twitch/Ustream streaming functionality and game DVR capabilities will all be available day-one. Users will also start out with the ability to play games as they download, use party chat, log-in using facial recognition via PlayStation Camera, navigate the home screen with voice commands, play games online and watch Blu-ray/DVD discs.
Other features, such as the PlayStation 4's low-power suspend/resume capabilities, will not be enabled on day one and will be added at a later date. Further information about which system functionalities will and won't be ready by launch day is coming "in the near future."