you can watch the sony briefing here if you missed it, or just want to rewatch the event
the Playstation 4 Briefing will be on Tuesday, August 12 at 10 am PDT / 1 pm EDT. the Briefing will be live-streamed on the PlayStation Blog through their Gamescom hub page and on Twitch. if you want more of a live blogging experience you can get updates via Facebook page or their EU Twitter feed. there is even a Playstation hashtag, #PlayStationGC , to keep you in the loop.
there will be hands-on booths set up for DRIVECLUB, Bloodborne, LittleBigPlanet 3 and The Order 1886