At the last Celebration, a Jader on volunteer duty ran into a fan who had heard that Hayden Christensen was attending and had driven hours just to see him. Alas, it was just a rumor and the Jader had to break the news that no, Hayden wasn’t coming.
Don’t let this happen to you! Remember that the only solid information on Celebration guests will come from StarWars.com or StarWarsCelebration.com, and you should always – always – check with them before taking any such ‘news’ to heart.
Yes, as a fansite, we’re not beyond posting rumors, but we do make an effort to clearly mark them as such… Authors, for instance, aren’t listed on those sites, but we always link to an official source. (Usually Del Rey on Facebook, these days.)
The same goes for all other cons. If there’s a guest you really want to see, always check the convention web site and/or the personalities’ personal page or Facebook fan page (assuming they have one and keep it updated) before committing to a convention. Also be aware that despite all this, sometimes things come up and people may have to cancel at the last minute.