Destiny's end-game PvP activity, Trials of Osiris, was supposed to return earlier this month. However, due to a bug that made Hunter's stupid overpowered, Bungie delayed its return until they could fix it. Although the latest patch did fix the problem, it was probably came too late to activate Trials this week; but, Bungie has confirmed its return.
Trials of Osiris will return in all its 3v3 Elimination glory on October 30th.
Trials of Osiris is "the ultimate test of teamwork and skill." Gear matters (no auto balancing) and matches are played in rounds (first to win 5 rounds wins the match), with no respawning during each individual round. The unique catch with Trials of Osiris is that you're given a scorecard at the start which keeps tracks of the matches you've won and lost during the week. The more wins you rack up before three losses, the better the rewards you can claim.
As a reminder, Bungie has made some changes to the mode in Year Two of Destiny. You can read up on all the changes here.
[Bungie]