Rockstar has revealed that the GTA Online: Bikers expansion announced last week will be out on October 4. It also put out a few more screens of rough-looking men on their mighty machines, and teased some of the new gameplay that the expansion will bring to the streets of Los Santos and beyond.
Bikers will have the ability to engage in melee combat with an assortment of new weapons while riding, which sounds pleasantly Road Rash-ish, although I'm sure (or at least hopeful) that the GTA gameplay will be somewhat more sophisticated. Club prospects must “earn the President's respect” in order to climb the ranks, an effort that can presumably be helped (or hurt, if ya ain't got what it takes) by bringing them along on the new MC Missions.
There's no trailer yet, so here's a link to a video of some other bikers. Screens are below.