The main update will be BOUNTY HUNTER
For those of you who remember PKing back in the day, Bounty Hunter is a minigame style activity where you are assigned a target, another player, and you must then hunt them down and try to defeat them. Along with being able to loot everything your opponent was wearing, you'll also earn points that can be redeemed for further rewards, like weapon/armor upgrades, the three weapons from the Crucible minigame and more.
Along with Bounty Hunter, Elite Skilling Outfits will be making their way into the main game. I believe the first two outfits will be the Magic Golem Outfit and it's lesser versions, along with the Infinity Ethereal Outfit and it's lesser versions. They will be obtainable through normal skilling methods. In the coming months, more of the Outfits will be released into the main game.
I will be updating this post as more information on Monday's update it released.