It took four years...but HomePlug AV is finally shipping from Zyxel: The 200 Mbps networking standard that works over home electrical wiring has taken quite a while to reach the market from its initial announcement. When I met with the HomePlug Alliance at CES this last January, they expected products within months. Still, even though there are two competing standards--each backed by a single firm--HomePlug has the industry mojo and will eventually catch on. The biggest consumer electronics and networking players back HomePlug.
HomePlug AV is designed around IPTV (Internet protocol television), which has millions of subscribers today and is expected to have tens of millions in a few years. With IPTV, a single pipe delivers TV programming, Internet access, and often telephony, too. Zyxel's first two products are an Ethernet adapter and a coax Ethernet adapter for $99 and $114, respectively. The coax adapter isn't well explained; I expect that it's a way for providers to pump data into the household over coax without requiring that the coax terminate at the settop box elsewhere in the house.
Oddly for a 200 Mbps raw throughput product, the Ethernet adapters run at 10/100 Mbps; gigabit Ethernet is apparently still too expensive to put into this class of device, but it should be a given in the near future because of the focus on having sufficient bandwidth to handle multiple video streams.
Several other manufacturers demonstrated HomePlug AV products a week ago, and more products are expected in the pipeline soon.