Facebook releases new Android platform: Messages and notifications redefined

Facebook CEO Mark Zuckerberg is expected to announce its first foray into the cellphone market during a 10 a.m. PT press event Thursday at his Menlo Park, Calif. headquarters.

ABC News technology editor Joanna Stern will anchor our live chat from Facebook headquarters and will be joined by Yahoo News columnist Rob Walker and editor Max Zimbert for a live chat about the social network's latest, and potentially most pivotal, mobile move.