On March 1st, Google Chromecast will officially start to sell in the UK. This is the first region outside USA where Chromecast will become officially available, and thereby probably marks the beginning of a global Chromecast rollout.
What is especially interesting with Chromecast, is the ability to stream e.g. Netflix on any TV with HDMI using only the Chromecast and your existing smartphone, tablet or laptop. Simply plug Chromecast into your TV, connect it to WiFi and start transmitting music or video from your phone, tablet or laptop to your TV.
Chromecast is $35 USD in US, why the expected price in the UK would be somewhat around 35 GBP. The official list of streaming services supported by Chromecast is available on the Chromecast website, but e.g. include both Netflix and YouTube. Services specifically for the UK region is expected to become available shortly after the UK release.
You can read more about Google Chromecast on its website