PS4 can't stream media from home PCs. Sony revealed the feature that allowed PS3 systems to access locally networked media servers to play music and videos will not appear in its next-gen system.
The omission was announced in a PS4 FAQ blowout posted today on the PlayStation Blog. Sony did not say why it elected to remove the feature, but that was unfortunately not the only media venue it axed.
Unlike PS3, PS4 will not play MP3s or audio CDs. That means the only known way to play music from the system is via Sony's Music Unlimited service, which requires a subscription.
You can always play music from an external system, or stream movies from Netflix and other services once they go live, but it's still a step back from the previous generation.