Sony Computer Entertainment Europe stats that they'll be streaming their press conference on Tuesday August 16th, 2011 starting at 8:00 AM PST and 11:00 AM EST. You can find the stream on the European PlayStation Blog, the PlayStation App, in PlayStation Home or on the PlayStation Facebook page.
Electronic Arts will also be sharing their press conference live on Tuesday August 16th, 2011. Their press conference will kick off at 7:00 AM PST and 10:00 AM EST. While normally at a conference you'd have to run from one presser to the next, EA's Gamescom site is located right here, which is only a click away.