It's a party and you are all invited. The celebration is June 23-29. Taking place on 20 regions. This year's theme is The Future of Virtual Worlds. I got a preview last night and this place looks very futuristic. Be sure to set your environment to midnight to take advantage of the cool lighting.
There is a lot of information here on the SL6B wiki, including a complete calendar of events.
Treet.tv will be streaming the opening ceremonies if you can't make it to the event. Just add this url to your land or media player : http://streams.treet.tv/live.mov There is also a really nice audio stream of cinema music available to you here : http://www.cinemix.us
Update 10:15 am SLT - Here is an alternative link to the video stream : http://www.ustream.tv/channel/treet-tv