Well yes and no. It's the latest for the majority of receivers at this time, but there is newer software out there, which will roll out to your receiver eventually, as long as they don't find any major hiccups in it. When things go well, it usually takes one or two weeks to get the update rolled out to everyone. If problems arise, it could be longer.
I have a single Hopper running S418nacb attached to a Samsung UN60F8000 that supports CEC. Ever since the S418nacb update on 11-19-2013 every morning my TV is on. The Hopper is off but sometime during the night the Hooper turned the TV back on. This has happened every single night except for a couple nights ago when I disconnected the HDMI cable from the Hopper to the TV. Anyone have any ideas what's going on or how to stop it?