Priced at US $15 and available at the Google Store, the Chromecast Ethernet adapter provides both data and power via USB port and pretty much looks like a power adapter with Ethernet port. The connectivity is limited to 10/100Mbps so no Gigabit connection there but should be better for those that have a limited or low WiFi signal near their TV.
According to early reports, Google Chromecast Ethernet adapter is already sold out at the US Google Store and should be available in Europe pretty soon so in case you have been struggling with limited WiFi connectivity on your Chromecast, this just might be the best accessory for you.