Indeed, we run multicast over 4 continents. One problem with multicast is the lack of real understanding by network engineers, because it's so rare (certainly anything that involves PIM), few people really get it, fewer tools are available to work out what's going on.

In the broadcast industry, multicast at a local level is very important though - with SDI being replaced by things like 2022-6 and 2110. I believe that's mainly at the IGMP/layer 2 level though, and there aren't many 2110 implementations over routers.