Sigh...
Doesn't anyone remember that from the beginning of the Xbox Live service for the X360, this was supposed to happen, but got delayed?
This has been a very, very long time coming. Its absolutely no suprise to me.
I you are arguing "it's gimping silver service!" but it's not. It's not like they are removing the service....Just delaying free demos a week for games.
It's not really a bad idea - when a demo comes out, Xbox Live runs at a snail's pace, slowing everything from downloads, to games down half of the time. If you can stagger the "release" of high-end demos (like AC6's demo, that had 500,000 demos it's first week....That's a ton of bandwidth), it will allow both gold and silver accounts better speeds to the same content.
Back from the dead, I'm afraid.