While the Celebration VI website recently posted a "What's Happening" page, only activities returning from CV are currently listed there. If you're anxious to find out more about the panels, guests, and entertainment for CVI, look no further than StarWars.com's Homing Beacon newsletter for an estimated timeframe. Here's what Homing Beacon #362 said:
"Watch for guest and entertainment announcements starting late September at www.starwarscelebration.com."
And then, in the paragraph about fan-produced activities:
"Look for more information starting late September, including the guidelines for proposing fan programming and signing up for fan tables."
That means we've got just about a month to go until we start hearing more concrete details about Celebration VI programming!