Japan Expo staff has made it possible for anyone to send their questions to CLAMP to be answered in their public conference at the event (similar to what was done for Anime Expo in 2006).
The event’s official website has more information on how to submit your question (basically you must fill a form).
The deadline is May 15.
They have also announced the day of CLAMP’s first public conference: Saturday, July 4.
LOL at their first question example: When the X series will be finished? I so wanna hear them answering that question for the thousandth time (and it’s the thousandth time and is even bolder, Teddy Picker, love this song xD).
Give it your best shot and ask away!