At CES 2007, Zyxel announced the DMA-1000, a digital media adapter for serving up multimedia files from the PCs in your home to your home entertainment system. The small adapter resembles a wireless router and, in fact, supports both wired and wireless connections via Ethernet and 802.11g Wi-Fi. In addition, it offers a USB port so that you can play files from any USB-based storage device, such as a flash thumbdrive or an MP3 player.
The DMA-1000 supports high-def streaming (1080i) and includes an HDMI connector, as well as S-Video. Unfortunately, 802.11g throughput is insufficient for HD streams, so you're probably better off using a wired PowerLine HD adapter for smooth video play. The DMA-1000 is UPnP and DLNA compliant, so it should play nicely with other UPnP and DLNA devices.
Zyxel expects to ship the $200 DMA-1000 in the first quarter of the year.