Microsoft announced new dates for their LIVE Weekends promotion where Silver members get to experience Gold member benefits for a limited time:
"During the free LIVE Weekends, all Xbox LIVE Silver members can enjoy: online multiplayer, Facebook, Twitter, Last.FM, Netflix, Sky Player, Halo Waypoint and 1 v 100*
Here is the schedule of when the freeness starts for Silver Members:
For all Xbox LIVE regions except those in Europe, Xbox LIVE Silver members will have free access from November 20th from 12n ET /9a PT /17:00 GMT until November 23rd from 12n ET /9a PT /17:00 GMT
For All European Xbox LIVE regions, Xbox LIVE Silver members will have free access from November 25th from 17:00 GMT until November 30th at 17:00 GMT
*Some features are only available in specific regions."