Elemental came to London to talk about its relationship with Sky in the UK, but with the news this week that Comcast is releasing its Stream service in the US, it is pretty obvious that Elemental is behind that service, in the process becoming the transcoding platform of choice for two of the largest broadcasters in the world. Back in December, when Sky in the UK made a $4 million investment in the US software encoder specialist, it was pounds to a penny that Sky was planning to use its encoding skills, and in the process likely replacing the existing Sky relationship with Envivio. This week at an event at Sky’s West London production facility, the two jointly announced that…