DLNA

DLNA (Digital Living Network Alliance) is the industry standard making all kind of AV-gear communicates with each other over the home network. It allows you to control one device with another, stream audio or video over the network, etc.
It is gaining momentum. What TCP/IP is for the internet, might DLNA become for AV-gear, a standard everyone adhere to.

More about DLNA

Enable media sharing

In the Control Panel choose HomeGroup to enable media sharing.

Win7 has all service needed running by default regardless if you put on media sharing or not.

SSDP Discovery

Discovers networked devices and services that use the SSDP discovery protocol, such as UPnP devices. Also announces SSDP devices and services running on the local computer. If this service is stopped, SSDP-based devices will not be discovered.

UPnPhost

Allows UPnP devices to be hosted on this computer. If this service is stopped, any hosted UPnP devices will stop functioning and no additional hosted devices can be added. If this service is disabled, any services that explicitly depend on it will fail to start.

WMPNetworkSvc

Shares Windows Media Player libraries to other networked players and media devices using Universal Plug and Play